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Synthesis of zero-valent iron nanoparticles via electrical wire explosion for efficient removal of heavy metals
, Article Clean - Soil, Air, Water ; Volume 45, Issue 3 , 2017 ; 18630650 (ISSN) ; Rabiee, H ; Seyed Shahabadi, S. M ; Borghei, S. M ; Sharif University of Technology
2017
Abstract
In this paper, electrical wire explosion (EWE) was used as a simple, clean, in situ method to synthesise nano zero-valent iron (nZVI) particles in liquid mediums. The structural and physical properties of the synthesised nZVI particles were characterised by x-ray diffraction, Brunauer–Emmett–Teller analysis, field emission scanning electron microscopy and transmission electron microscopy. The synthesised spherical nanoparticles, at a specific size of 10–50 nm, possessed large surface areas of approximately 13.27 m2/g, reinforcing the significant advantages of EWE, that is, less aggregation and in situ production of nanoparticles with enhanced removal efficacy, for groundwater treatment....
High flux electrospun nanofiberous membrane: Preparation by statistical approach, characterization, and microfiltration assessment
, Article Journal of the Taiwan Institute of Chemical Engineers ; Volume 59 , 2016 , Pages 474-483 ; 18761070 (ISSN) ; Mousavi, S. A ; Bastani, D ; Sharif University of Technology
Taiwan Institute of Chemical Engineers
2016
Abstract
Preparation, characterization and evaluation of new generation of micro-filters based on polyacrylonitrile electrospun nanofiberous membrane (ENM) were thoroughly investigated. First, quantitative relationships between average diameter, bead area density of nano-fibers and certain electrospinning parameters, i.e., concentration, voltage, spinning distance, and feed rate, were established by empirical modeling based on a central composite design. The analysis revealed that concentration, voltage and distance are the significant parameters. Also, adequacy checking indicated the appropriateness of fit for the models. Afterwards, bead-free ENMs with diameter of 100-500 nm were prepared and...
High flux electrospun nanofiberous membrane: Preparation by statistical approach, characterization, and microfiltration assessment
, Article Revista Mexicana de Urologia ; Volume 76, Issue 1 , 2016 , Pages 474-483 ; 01854542 (ISSN) ; Mousavi, S. A ; Bastani, D ; Sharif University of Technology
Elsevier Doyma Mexico
2016
Abstract
Preparation, characterization and evaluation of new generation of micro-filters based on polyacrylonitrile electrospun nanofiberous membrane (ENM) were thoroughly investigated. First, quantitative relationships between average diameter, bead area density of nano-fibers and certain electrospinning parameters, i.e., concentration, voltage, spinning distance, and feed rate, were established by empirical modeling based on a central composite design. The analysis revealed that concentration, voltage and distance are the significant parameters. Also, adequacy checking indicated the appropriateness of fit for the models. Afterwards, bead-free ENMs with diameter of 100-500 nm were prepared and...
Optimization of operating conditions in ultrafiltration process for produced water treatment via Taguchi methodology
, Article Desalination and Water Treatment ; Volume 54, Issue 10 , June , 2015 ; ISSN: 19443994 ; Sepehrinia, K ; Seyed Shahabadi, S. M ; Rekabdar, F ; Gheshlaghi, A ; Sharif University of Technology
2015
Abstract
This paper describes how to find optimal operating conditions of three controlling parameters, i.e. temperature, transmembrane pressure (TMP), and cross-flow velocity (CFV) for maximizing the permeate flux and total organic carbons (TOC) rejection, and minimizing the fouling resistance using Taguchi method in ultrafiltration (UF) treatment of the real produced water. At first, the optimal operating conditions were found at a temperature of 45°C, TMP = 4 bar, and CFV of 2.25 m/s. To determine the most significant parameters affecting the response parameters, an analysis of variance was employed. In the second stage, performance of applied polymeric membrane in the UF system was studied under...
Optimization of operating conditions in ultrafiltration process for produced water treatment via Taguchi methodology
, Article Desalination and Water Treatment ; Volume 54, Issue 10 , May , 2015 , Pages 2669-2680 ; 19443994 (ISSN) ; Sepehrinia, K ; Seyed Shahabadi, S. M ; Rekabdar, F ; Gheshlaghi, A ; Sharif University of Technology
Taylor and Francis Inc
2015
Abstract
This paper describes how to find optimal operating conditions of three controlling parameters, i.e. temperature, transmembrane pressure (TMP), and cross-flow velocity (CFV) for maximizing the permeate flux and total organic carbons (TOC) rejection, and minimizing the fouling resistance using Taguchi method in ultrafiltration (UF) treatment of the real produced water. At first, the optimal operating conditions were found at a temperature of 45°C, TMP = 4 bar, and CFV of 2.25 m/s. To determine the most significant parameters affecting the response parameters, an analysis of variance was employed. In the second stage, performance of applied polymeric membrane in the UF system was studied under...
Superhydrophobic dual layer functionalized titanium dioxide/polyvinylidene fluoride-co-hexafluoropropylene (TiO2/PH) nanofibrous membrane for high flux membrane distillation
, Article Journal of Membrane Science ; Volume 537 , 2017 , Pages 140-150 ; 03767388 (ISSN) ; Rabiee, H ; Seyedi, S. M ; Mokhtare, A ; Brant, J. A ; Sharif University of Technology
Elsevier B.V
2017
Abstract
In this study, superhydrophobic dual layer membranes with highly porous structure were fabricated using electrospinning and electrospraying techniques. Electrospinning method was used to produce the support nanofibrous layer using polyvinylidene fluoride-co-hexafluoropropylene (PH) as the polymer and a mixed solvent system of N,N-Dimetylformamide (DMF) and acetone. Afterwards, hydrophobic, functionalized TiO2 nanoparticles were deposited on the surface of the support layer using the electrospraying technique. TiO2 chemical functionalization and their deposition on the support layer were investigated by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy. The...
Preparation and Characterization of Electrospun Nanofiberous Membranes for Wastewater Treatment
, M.Sc. Thesis Sharif University of Technology ; Bastani, Daruoosh (Supervisor) ; Moosavi, Ali (Supervisor)
Abstract
The aim of the current project is preparation, characterization and microfiltration evaluation of nanofiberous membrane. In order to prepare membranes, the electrospinning method was utilized and polyacrylonitrile and N-N, dimethylformamide (DMF) were used as the polymer and the solvent, respectively. As the nanofiber diameter controls the structure of the membrane and also bead formation reduces the membrane uniformity, at first the effects of four most influential electrospinning parameters, such as solution concentration, applied voltage, floe rate, and the distance between needle tip and the collector, on average fiber diameter and bead area density were investigated via response surface...
Analysis of terahertz-induced optical phase modulation in a nonlinear dielectric slab
, Article Progress In Electromagnetics Research M ; Volume 13 , 2010 , Pages 41-51 ; 19378726 (ISSN) ; Izadi, S. A ; Shahabadi, M ; Sharif University of Technology
2010
Abstract
Frequency shift of the spectrum of an incident optical pulse by an intense THz pulse inducing cross-phase modulation (XPM) in a nonlinear dielectric slab is analyzed. The effect is predicted with a high degree of accuracy using the well-known transmission line matrix (TLM) technique. In this research, to model the THz-induced temporal and spatial variation of the dielectric permittivity of the nonlinear dielectric slab, the transmission lines of the TLM method are loaded with open shunt stubs. The parameters of the stubs are modified in accordance with the refractive index variation of the dielectric slab, here ZnTe, induced by the strong THz pulse. The obtained numerical results are...
On the h-vector of a simplicial complex with Serre's condition
, Article Journal of Pure and Applied Algebra ; Volume 216, Issue 1 , January , 2012 , Pages 91-94 ; 00224049 (ISSN) ; Pournaki, M. R ; Seyed Fakhari, S. A ; Yassemi, S
2012
Abstract
Let δ be a (d-1)-dimensional simplicial complex and let h(δ)=(h0,h1,...,hd) be its h-vector. A recent result of Murai and Terai guarantees that if δ satisfies Serre's condition (Sr), then (h0,h1,...,hr) is an M-vector and hr+hr+1+...+hd is nonnegative. In this article, we extend the result of Murai and Terai by giving r extra necessary conditions. More precisely, we prove that if δ satisfies Serre's condition (Sr), then iihr+i+1ihr+1+...+i+d-rihd, 0≤i≤r≤d, are all nonnegative
Extremely Emissive V-Grooved Microstructure Made of SU-8 for Enhanced Radiative Cooling
, Article IEEE Photonics Journal ; Volume 15, Issue 4 , 2023 ; 19430655 (ISSN) ; Badieirostami, M ; Shahabadi, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2023
Abstract
For a structure to show radiative cooling property, it must have first, high reflectivity of above 90% in the wavelength range of 0.3 to 3 μm, and second, high emissivity for the wavelengths ranging from 8 to 13 μm, namely atmospheric transparency window. Being inspired by the architecture of microwave absorbers used extensively for antenna measurements, we proposed a novel microstructure with near unity emissivity that can be further developed for radiative cooling. To this end, we designed and analyzed a V-grooved multilayer periodic microstructure capable of perfectly emitting in the aforementioned wavelength range. Further, SU-8 is selected as the material of the proposed microstructure....
Design of a wideband terahertz absorber composed of graphene patches
, Article IET Optoelectronics ; Volume 13, Issue 5 , 2019 , Pages 235-239 ; 17518768 (ISSN) ; Maddahali, M ; Bakhtafrouz, A ; Shahabadi, M ; Sharif University of Technology
Institution of Engineering and Technology
2019
Abstract
Here, the design of a wideband absorber operating at terahertz frequencies is presented. The design is based on an analytical circuit model of graphene arrays of rectangular patches obtained from the presented circuit model of graphene arrays of disks. A recently proposed method is generalised for the design of wideband absorbers at higher frequencies The bandwidth is increased by correct tuning of the input impedance for a structure composed of two layers of graphene arrays and a metal-backed dielectric layer. Using two-layer graphene arrays, the authors decrease the slope of the imaginary part of the input impedance to increase the bandwidth. The designed absorber works at a frequency of...
Investigation of shear lag effect on tension members fillet-welded connections consisting of single and double channel sections
, Article Structural Engineering and Mechanics ; Volume 74, Issue 3 , 2020 , Pages 445-455 ; Maleki, S ; Mirtaheri, M ; Nazeryan, M ; Seyed Mahdi, M. S ; Sharif University of Technology
Techno Press
2020
Abstract
Shear lag phenomenon has long been taken into consideration in various structural codes; however, the AISC provisions have not proposed any specific equation to calculate the shear lag ratio in some cases such as fillet-welded connections of front-to-front double channel sections. Moreover, those equations and formulas proposed by structural codes are based on the studies that were conducted on riveted and bolted connections, and can be applied to single channel sections whilst using them for fillet-welded double channels would be extremely conservative due to the symmetrical shape and the fact that bending moments will not develop in the gusset plate, resulting in less stress concentration....
Investigation of deformation mechanism in polypropylene/glass fiber composite
, Article Journal of Applied Polymer Science ; Volume 87, Issue 13 , 2003 , Pages 2171-2176 ; 00218995 (ISSN) ; Bagheri, R ; Seyed Reihani, S. M ; Forunchi, M ; Sharif University of Technology
2003
Abstract
A great amount of work has been done over the past few years to understand the structure-properties relationship in polypropylene/glass fiber composites. This is because of the very fast-growing rate of polypropylene applications in the automotive and other industries. This work focused on the role of glass fibers and fiber-matrix adhesion on deformation mechanism. Composites with different fiber content, with and without adhesion promoter, were fabricated. Tensile tests and microscopy techniques were conducted. Based on the results, a physical model has been proposed that illustrates the initiation and growth of the damage under static loading condition. According to this work, the...
Predictive analytics for fault reasoning in gas flow control facility: A hybrid fuzzy theory and expert system approach
, Article Journal of Loss Prevention in the Process Industries ; Volume 77 , 2022 ; 09504230 (ISSN) ; Nourian, R ; Mousavi, S. M ; Seyed Alizadeh, S. M ; Memarpour, M ; Sharif University of Technology
Elsevier Ltd
2022
Abstract
Gas pressure reduction stations are essential in energy distribution networks because even a minor failure of these systems causes disruptive consumer problems. This study aims to introduce and implement a new knowledge-based platform that uses the synthesized expert's opinions to improve gas pressure control facilities. Given the record of failure of gas transmission system components and the data's uncertain nature, a new fuzzy expert system is developed that takes advantage of the object-oriented programming paradigm to analyze failure modes and conditions. The artificial intelligent model is designed in C# programming language, and a user-friendly interface is developed for ease of...
Aging behaviors of Al 6061 and Al 6061/ SiCp composite
, Article Advanced Materials Research ; Volume 410 , 2012 , Pages 240-244 ; 10226680 (ISSN) ; 9783037853160 (ISBN) ; Ekrami, A ; Seyed Reihani, S. M ; Mousavi Abarghouie, S. M. R ; Sharif University of Technology
2012
Abstract
In the present research the aging behavior of Al6061 alloy and Al6061/SiCp composite fabricated by powder metallurgy method was investigated. The solution treatment of the samples were carried out at 527°C for 2, 3and 4 h followed by aging at 180°C for different aging times between 1 and 10 h. The existence of SiC particles led to increasing the peak hardness of the composite. The peak hardness of the composite took place at shorter times than that of the 6061 alloy for the samples solution treated for 3and 4 h, but took place at longer times for the samples solution treated for 2 h. The optimum solution treating time was about 3 h for both the composite and the 6061 alloy that led to the...
The clique numbers of regular graphs of matrix algebras are finite
, Article Linear Algebra and Its Applications ; Volume 431, Issue 10 , 2009 , Pages 1715-1718 ; 00243795 (ISSN) ; Jamaali, M ; Seyed Fakhari, S. A ; Sharif University of Technology
2009
Abstract
Let F be a field, char (F) ≠ 2, and S ⊆ GLn (F), where n is a positive integer. In this paper we show that if for every distinct elements x, y ∈ S, x + y is singular, then S is finite. We conjecture that this result is true if one replaces field with a division ring. © 2009 Elsevier Inc. All rights reserved
Mechanical induced reaction in Al-CuO system for in-situ fabrication of Al based nanocomposites
, Article Journal of Alloys and Compounds ; Volume 465, Issue 1-2 , 2008 , Pages 151-156 ; 09258388 (ISSN) ; Simchi, A ; Seyed Reihani, S. M ; Sharif University of Technology
2008
Abstract
Gradual chemical (displacement) reaction between CuO and Al powders during high-energy attrition milling under a high purity argon atmosphere was studied. Differential thermal analysis (DTA), X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques were employed to study the solid-state reaction. It was shown that the solid-state reaction occurred during mechanical alloying (MA) and resulted in the dissolution of copper into the aluminum lattice and formation of nanometric alumina particles. The reinforcement particles were mostly distributed at the grain boundaries of Al matrix with an average crystallite size of about 50 nm. In DTA curve of the milled powders, a small...
Improved photon to current conversion in nanostructured TiO2 dye-sensitized solar cells by incorporating cubic BaTiO3 particles deliting incident
, Article Solar Energy ; Volume 132 , 2016 , Pages 1-14 ; 0038092X (ISSN) ; Mohammadi, M. R ; Seyed Reyhani, S. M ; Sharif University of Technology
Elsevier Ltd
2016
Abstract
Different structures of dye-sensitized solar cells (DSCs) were fabricated with various compositions and arrangement modes of the photoanodes. The solvothermally grown TiO2 nanoparticles and sol-gel derived spherical TiO2 and BaTiO3 particles were employed as the active and scattering layers of DSCs. TiO2 nanoparticles and spherical particles had pure anatase structure with particle size of 15-30 nm and 200-400 nm, respectively, whereas 300-800 nm BaTiO3 particles showed cubic perovskite structure. The efficiency improvement of mono-layer cells made of TiO2 nanoparticles (i.e., 7.22%) was achieved by light harvesting mechanism. Further enhancement of photovoltaic performance was achieved by...
Utilizing a simulation approach for analysis of patient flow in the emergency department: a case study
, Article 15th Iran International Industrial Engineering Conference, IIIEC 2019, 23 January 2019 through 24 January 2019 ; 2019 , Pages 151-157 ; 9781728117751 (ISBN) ; Haji, B ; Shakhsi Niaei M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Simulation has been shown to be one of the most powerful tools in many areas of the health-care system, a system which attracted the attention of researchers due to its intricacy. The main goal of this study is to evaluate the patients' flow in an emergency department (ED). Discrete event simulation (DES)has been used as the core of this research so that it offers various ways to reduce the length of stay (LOS)of patients in different segments of ED by assessing various scenarios. In particular, a new approach for verification of the simulated model will be discussed. This study reports on the results that extracted from a case study on patient record data in one of the EDs located in Tehran...
Fracture mechanism under dynamic loading of elastomer-modified polypropylene
, Article Materials Letters ; Volume 57, Issue 18 , 2003 , Pages 2733-2741 ; 0167577X (ISSN) ; Lazzeri, A ; Bagheri, R ; Seyed Reihani, S. M ; Frounchi, M ; Sharif University of Technology
2003
Abstract
In last decades, rubber-toughened polymer blends have been the object of considerable interest by many investigators, owing to their attractive mechanical as well as physical properties. Polypropylene (PP) is a type of polyolefin which can be toughened using rubber particles. In another paper [J. Appl. Polym. Sci., submitted for publication], the role of ethylene-propylene (EPR) particles on the deformation mechanism during tensile tests and the fracture mechanism under quasi-static loading tests has been investigated. This paper is instead focused on the role of EPR particles on the fracture mechanism under dynamic loading (impact properties) of EPR/PP blends. Blends with different weight...