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Polypyrrole-polyaniline/Fe3O4 magnetic nanocomposite for the removal of Pb(II) from aqueous solution
Seyed Abolfazl Seyed Sadjadi,Amirhossein Afshar,Afsaneh Mollahosseini,Mohammadreza Eskandarian 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.2
Lead ion which is engaged in aqueous solution has been successfully removed. A novel technique was utilized for the separation and absorption of Pb(II) ions from aqueous solution. Magnetic Fe3O4 coated with newly investigated polypyrrole-polyaniline nanocomposite was used for the removal of extremely noxious Pb(II). Characteristic of the prepared magnetic nanocomposite was done using X-ray diffraction pattern, Field emission scanning electron microscopy (FE-SEM), Fourier transform-infra red spectroscopy (FT-IR) and energy dispersive x-ray spectroscopy (EDX). Up to 100% adsorption was found with 20mg/L Pb(II) aqueous solution in the range of pH=8-10. Adsorption results illustrated that Pb(II) removal efficiency by the nanocomposite increased with an enhance in pH. Adsorption kinetics was best expressed by the pseudo-second-order rate form. Isotherm data fitted well to the Freundlich isotherm model. Upon using HCl and HNO3, 75% PPy-PAn/Fe3O4 nanocomposite, desorption experiment showed that regenerated adsorbent can be reused successfully for two successive adsorption-desorption cycles without appreciable loss of its original capacity.
Seyed Mohammad Seyed Alizadeh Ganji,Seied Ziaeddin Shafaei,Nasser Goudarzi,Asghar Azizi 한국자원공학회 2016 Geosystem engineering Vol.19 No.1
This study is aimed at determining the optimum mixing ratio and solvent group to extract REEs from nitric leach solution, and the efficiency was tested using three different kinds of extractants, which were prepared to mix three different solvents of Cyanex272, D2EHPA, and HQ. In order to select the best mixture system, different volumes (ml) of solvent extractions were used under optimum conditions (.05 M concentration and pH of 2). The result indicated that the mixture system of Cyanex272 (8 ml) and D2EHPA (2 ml) had the highest separation factor and enrichment ratio in the separation of rare earth element, especially dysprosium. The degree of performance of mixture systems in separation of the rare earth elements indicated that the best extraction systems were in the order of Cyanex272 (8 ml) and D2EHPA (2 ml) > HQ (2 ml) and D2EHPA (8 ml) > Cyanex272 (8 ml) and HQ (2 ml).
Hashemi, Seyed Hossein,Dehghani, Seyed Ali Mousavi,Khodadadi, Abdolhamid,Dinmohammad, Mahmood,Hosseini, Seyed Mohsen,Hashemi, Seyed Abdolrasoul The Korean Institute of Chemical Engineers 2017 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.55 No.5
In the present research, in order to predict activity coefficient of inorganic ions in electrolyte solution of a petroleum system, we studied 13 components in the electrolyte solution, including $H_2O$, $CO_2$ (aq), $H^+$, $Na^+$, $Ba^{2+}$, $Ca^{2+}$, $Sr^{2+}$, $Mg^{2+}$, $SO_4$, $CO_3$, $OH^-$, $Cl^-$, and $HCO_3$. To predict the activity coefficient of the components of the petroleum system (a solid/liquid equilibrium system), activity coefficient model of Extended UNIQUAC was studied, along with its adjustable parameters optimized based on a genetic algorithm. The total calculated error associated with optimizing the adjustable parameters of Extended UNIQUAC model considering the 13 components under study at three temperature levels (298.15, 323.15, and 373.15 K) using the genetic algorithm is found to be 0.07.
Seyed Mehdi Mirkazemi Niyaragh,Aref Jalili Irani,Hossein Shayeghi 대한전기학회 2020 Journal of Electrical Engineering & Technology Vol.15 No.6
In this research, Zero Injection Buses (ZIBs) were modeled to minimize the number of Phasor Measurements Units (PMUs) and ensure the full observability of power systems. To determine the operation of the proposed method, all ZIBs that are connected to each other and other buses were presented in models H, M, and D, each of which featured new observability constraints. The H set, is defi ned as the set of buses that are connected to a ZIB. Also, the M set is defi ned as the H set that is connected through ZIBs. The D set is defi ned as the M set that is connected through ZIBs to a common bus. To increase the assurance of complete power system observability in the method put forward in this work, conditions such as line outage, single PMU loss, and line or PMU exit were examined. To demonstrate the effi ciency of the approach, it was applied to 14, 30, 39, 57 and 118 IEEE test systems. The simulation results showed that the developed topologies enhanced network observability under a minimum number of PMUs.
Seyed Sajad Mirjavadi,Masoud Forsat,Mohammad Reza Barati,AMS Hamouda 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.36 No.1
The present research investigates post-buckling behavior of geometrically imperfect tapered curved micro-panels made of graphene oxide powder (GOP) reinforced composite. Micro-scale effects on the panel structure have been included based on strain gradient elasticity. Micro-panel is considered to be tapered based on thickness variation along longitudinal direction. Weight fractions of uniformly and linearly distributed GOPs are included in material properties based on Halpin-Tsai homogenization scheme considering. Post-buckling curves have been determined based on both perfect and imperfect micro-panel assumptions. It is found that post-buckling curves are varying with the changes of GOPs weight fraction, geometric imperfection, GOP distribution type, variable thickness parameters, panel curvature radius and strain gradient.
Seyed Sajad Mirjavadi,Masoud Forsat,Mohammad Reza Barati,A.M.S. Hamouda 국제구조공학회 2020 Steel and Composite Structures, An International J Vol.36 No.1
A multi-scale epoxy/CNT/fiberglass annular sector plate is studied in this paper in the view of determining nonlinear forced vibration characteristics. A 3D Mori-Tanaka model is employed for evaluating multi-scale material properties. Thus, all of glass fibers are assumed to have uni-direction alignment and CNTs have random diffusion. The geometry of annular sector plate can be described based on the open angle and the value of inner/outer radius. In order to solve governing equations and derive exact forced vibration curves for the multi-scale annular sector, Jacobi elliptic functions are used. Obtained results demonstrate the significance of CNT distribution, geometric nonlinearity, applied force, fiberglass volume, open angle and fiber directions on forced vibration characteristics of multi-scale annular sector plates.
SEYED MOHAMMAD MIRVAKILI,MASOOMEH ALIZADEH KAVAFSHARY,ATIYEH JOZE VAZIRI 한국원자력학회 2015 Nuclear Engineering and Technology Vol.47 No.3
The research carried out on thorium-based fuels indicates that these fuels can be considered as economic alternatives with improved physical properties and proliferation resistance issues. In the current study, neutronic assessment of UO2 in comparison with two (Th-233U)O2, and (Th-235U)O2 thorium-based fuel loads in a heavy water research reactor has been proposed. The obtained computational data showed both thorium-based fuels caused less negative temperature reactivity coefficients for the modeled research reactor in comparison with UO2 fuel loading. By contrast, 233U-containing thorium-based fuel and 235U-containing thorium-based fuel loadings in the thermal core did not drastically reduce the effective delayed neutron fractions and delayed neutron fractions compared to UO2 fuel. A provided higher conversion factor and lower transuranic production in the research core fed by the thorium-based fuels make the fuel favorable in achieving higher cycle length and less dangerous and costly nuclear disposals.
Field test investigation and numerical analysis of ballasted track under moving locomotive
Seyed-Ali Mosayebi,Jabbar Ali Zakeri,Morteza Esmaeili 대한기계학회 2016 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.30 No.3
This paper is devoted to investigating of dynamic behavior of a ballasted railway track by field tests and numerical analyses. In this regard, at first in a field test program, two different sections in a ballasted track including concrete and wooden sleepers with good quality are selected and their dynamic vertical deflections are measured due to moving locomotive. In continuation, the numerical model of vehicle track interaction is developed and its results are verified using the measured values in the field tests and the previous research studies. Finally, using the verified model, a series of sensitivity analyses are accomplished on effecting parameters including sleeper type and track modulus. Results indicate that the dynamic behavior of the ballasted track under moving locomotive is linear with concrete sleepers while non-linear with wooden sleepers.
Seismic response of RC frames under far-field mainshock and near-fault aftershock sequences
Seyed Amin Hosseini,Jorge Ruiz-García,Ali Massumi 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.72 No.3
Engineered structures built in seismic-prone areas are affected by aftershocks in addition to mainshocks. Although aftershocks generally are lower in magnitude than that of the mainshocks, some aftershocks may have higher intensities; thus, structures should be able to withstand the effect of strong aftershocks as well. This seismic scenario arises for far-field mainshock along with near-field aftershocks. In this study, four 2D reinforced concrete (RC) frames with different numbers of stories were designed in accordance with the current Iranian seismic design code. As a way to evaluate the seismic response of the case-study RC frames, the inter-story drift ratio (IDR) demand, the residual inter-story drift ratio (RIDR) demand, the Park-Ang damage index, and the period elongation ratio can be useful engineering demand parameters for evaluating their seismic performance under mainshock-aftershock sequences. The frame models were analyzed under a set of far-field mainshock, near-fault aftershocks seismic sequences using nonlinear dynamic time-history analysis to investigate the relationship among IDR, RIDR, Park-Ang damage index and period ratio experienced by the frames. The results indicate that the growth of IDR, RIDR, Park-Ang damage index, and period ratio in high-rise and short structures under near-fault aftershocks were significant. It is evident that engineers should consider the effects of near-fault aftershocks on damaged frames that experience far-field mainshocks as well.
Seyed Ali Mousavi Davoudi,Morteza Naghipour 한국강구조학회 2020 International Journal of Steel Structures Vol.20 No.5
Concrete-fi lled steel tubular (CFT) columns have been widely used as structural members in buildings and bridges in recent years, because of their properties, such as high strength and stiff ness, good ductility, and convenience for construction. In CFT columns, the bearing capacity of columns is inversely related to buckling, therefore, buckling is of particular importance at these sections, the AISC Code uses eff ective bending rigidity ( EI eff ective ) to calculate the critical buckling load in concrete fi lled steel columns, to apply the eff ect of reducing concrete confi nement, the AISC code provides a maximum value of 0.9 of the reduced concrete confi nement coeffi cient for the equation. Eff ective bending rigidity ( EI eff ective ), this relationship is provided in AISC code for circular and square sections, therefore, the eff ect of the column shape geometry on the core concrete confi nement is very infl uential and changes the eff ective bending rigidity ( EI eff ective ) of the section. The AISC code does not provide a coeffi cient to consider the type of cross-sectional geometry in CFT columns, therefore, in this study, three groups experimental, numerical (FEM) and theoretical were used to provide critical buckling load correction, fi nally, it was concluded that the critical buckling load for the cross-section (L) shape due to the lower confi nement of the concrete core is 20.07% lower than the AISC code equation, also with a 67% increase in slenderness ratio, the critical buckling load decreased by 14.52%.