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Analyzing mixing quality in a curved centrifugal micromixer through numerical simulation
, Article Chemical Engineering and Processing: Process Intensification ; 2017 ; 02552701 (ISSN) ; Vatankhah, P ; Akbari, A ; Sharif University of Technology
Elsevier B.V
Abstract
The Lab On a CD (LOCD), also known as Centrifugal Microfluidics, has evolved into a sophisticated platform for performing biomedical assays due to its marvelous miniaturization and accurate simulation of biological reactions. Among the numerous applications of the LOCD is fluid mixing. In this paper a centrifugal, serpentine micromixer is simulated and reformed toward better mixing performance. The micromixer was chosen to be curved as a curved design was found to be thrice as functional and compact as a rectilinear design, mixing-wise. The two angular velocity and opening radius parameters were originally hypothesized to affect mixing performance. Effect of angular velocity was studied over...
Numerical simulation of centrifugal serpentine micromixers and analyzing mixing quality parameters
, Article Chemical Engineering and Processing: Process Intensification ; Volume 104 , 2016 , Pages 243-252 ; 02552701 (ISSN) ; Madadelahi, M ; Akbari, A ; Sharif University of Technology
Elsevier, B.V
2016
Abstract
Centrifugal microfluidics or the Lab on a CD (LOCD) has developed vast applications in biomedical researches and analyses. Fluid mixing is an application of the LOCD. In this paper, multiple centrifugal micromixers were simulated. Various parameters were originally presumed to have an effect on mixing performance. These parameters include inlet angle, angular velocity, cross-sectional profile, perpendicular length ratio and the number of channels in series. They were each analyzed through simulations. It was gathered that the inlet angle does not significantly affect the mixing quality. Increasing angular velocity steadily increases mixing quality for all geometries. The vertical triangular...
Analyzing mixing quality in a curved centrifugal micromixer through numerical simulation
, Article Chemical Engineering and Processing: Process Intensification ; Volume 116 , 2017 , Pages 9-16 ; 02552701 (ISSN) ; Vatankhah, P ; Akbari, A ; Sharif University of Technology
Elsevier B.V
2017
Abstract
The Lab On a CD (LOCD), also known as Centrifugal Microfluidics, has evolved into a sophisticated platform for performing biomedical assays due to its marvelous miniaturization and accurate simulation of biological reactions. Among the numerous applications of the LOCD is fluid mixing. In this paper a centrifugal, serpentine micromixer is simulated and reformed toward better mixing performance. The micromixer was chosen to be curved as a curved design was found to be thrice as functional and compact as a rectilinear design, mixing-wise. The two angular velocity and opening radius parameters were originally hypothesized to affect mixing performance. Effect of angular velocity was studied over...
Investigation of the performance of modified organic Rankine cycles (ORCs) and modified trilateral flash cycles (TFCs) assisted by a solar pond
, Article Solar Energy ; Volume 182 , 2019 , Pages 361-381 ; 0038092X (ISSN) ; Akbari, A ; Khalilian, M ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Solar pond is a type of solar collector that stores solar energy in the form of heat. The solar pond can be used as a low-temperature heat source for electricity generation. In this paper, to find the most suitable power cycle for power generation from the solar pond, the performance of the Organic Rankine Cycle (ORC), Trilateral Flash Cycle (TFC) and their modified forms with an open feed liquid heater and an internal heat exchanger for different working fluids was investigated. Water was considered as the heat transfer fluid which transfers the stored heat from the solar pond to the working fluid of the cycle. The results indicate that in all cases, the energy and exergy efficiency of the...
Nano-TiO2: An eco-friendly and re-usable catalyst for the synthesis of 14-aryl or alkyl-14H-dibenzo[a,j]xanthenes
, Article Journal of the Iranian Chemical Society ; Volume 8, Issue SUPPL. 1 , February , 2011 , Pages S129-S134 ; 1735207X (ISSN) ; Bamoniri, A ; Akbari, A ; Taghavinia, N ; Sharif University of Technology
2011
Abstract
Synthesis of 14-aryl or alkyl-14H-dibenzo[a,j]xanthenes using nano-TiO 2 as eco-friendly and efficient catalyst is reported. Short reaction times, high yields, a clean process, simple methodology, easy work-up and green conditions are advantages of this protocol
Double network hydrogel of sodium alginate/polyacrylamide cross-linked with POSS: Swelling, dye removal and mechanical properties
, Article International Journal of Biological Macromolecules ; Volume 129 , 2019 , Pages 187-197 ; 01418130 (ISSN) ; Akbari, A ; Eftekhari Sis, B ; Sharif University of Technology
Elsevier B.V
2019
Abstract
In this work, for the first time, we presented a novel design strategy to fabricate a new type of Octa-aminopropyl polyhedral oligomeric silsesquioxane hydrochloride salt (OA-POSS)-based Alg/PAAm DN gels, consisting of PAAm gel as the first chemical network and Alg/OA-POSS gel as the second chemical-physical network. Incorporation of OA-POSS nanoparticles with various feed ratio into the second network not only led to form strong coordination interactions but also in comparison to the other Alg/PAAm gels demonstrated superior mechanical properties. pH, temperature, contact time and salt effects parameters were studied on the swelling and dye removal properties of the synthesized DN hybrid...
Environmental evaluation and assessment of some important factors of oil contamination in soil around sarkhoun gas refinery of ar abbas
, Article Journal of Environmental Studies ; Volume 37, Issue 57 , 2011 , Pages 9-18 ; 10258620 (ISSN) ; Shayegan, J ; Malakouti, M. J ; Akbari, A ; Sharif University of Technology
Abstract
Hydrocarbon contaminations due to their volatility, solubility and biodegradability properties can enter the vadose zone and adversely influence the soil properties. Recently, some deep and superficial signs of oil pollution have emerged in the soils around the refinery of Sarkhoun. In order to assess the exact type and behavior of pollutants, evaluate the environmental attributes and measure some important factors of oil contamination in this region, and also to see how pollution transfer in the underground environment, this study has been done. Materials & methods Sarkhoun refinery is located 50 kilometers away from ar Abbas in the northeast direction. The area is mostly composed of Marne...
Synthesis of new 2-aryl-4-chloro-3-hydroxy-1H-indole-5,7-dicarbaldehydes via Vilsmeier-Haack reaction
, Article Journal of Heterocyclic Chemistry ; Volume 47, Issue 2 , 2010 , Pages 463-467 ; 0022152X (ISSN) ; Zirak, M ; Akbari, A ; Hashemi, M. M ; Sharif University of Technology
2010
Abstract
(Chemical Equation Presented) New 2-aryl-4-chloro-3-hydroxy-1H-indole-5,7- dicarbaldehydes were synthesized in three steps from acetophenone derivatives. By oxidation of acetophenones to aryl glyoxals using selenium dioxide and condensation with acetylacetone in the presence of ammonium acetate in water 3-acetyl-5-aryl-4-hydroxy-2-methyl-1H-pyrrols were obtained. 2-Aryl-4-chloro-3-hydroxy-1H-indole-5,7-dicarbaldehydes were synthesized via Vilsmeier-Haack reaction of pyrrole derivatives in moderate yields
Investigation of hydrocarbon pollution spreading in soil around sarkoun refinery
, Article 8th World Congress of Chemical Engineering: Incorporating the 59th Canadian Chemical Engineering Conference and the 24th Interamerican Congress of Chemical Engineering, 23 August 2009 through 27 August 2009, Montreal, QC ; 2009 , Pages - ; Malakouti, M. J ; Shayegan, J ; Atashjameh, A ; Akbari, A ; Sharif University of Technology
Abstract
The pollution existence around Sarkhoun refinery and the way of its probable present existence were studied. Due to the lack of underground water in the area and the existence of hardpans near to soil surface, pollution spread through vapor and hydrocarbon condensations in vados zone. Hydrocarbon pollution mostly occurred in the north of refinery which means in the place of the evaporation basin of phase 1 and the old evaporation basin of phase 2 in that side a part of the pollution was observed in the east of the refinery, which was related to the tube lines breakage. However, it was expected the pollution to spread towards center and west parts of the refinery, but the investigations...
Real space renormalization of majorana fermions in quantum nano-wire superconductors
, Article Journal of the Physical Society of Japan ; Volume 86, Issue 2 , 2017 ; 00319015 (ISSN) ; Langari, A ; Akbari, A ; Kim, K. S ; Sharif University of Technology
Abstract
We develop the real space quantum renormalization group (QRG) approach for majorana fermions. As an example we focus on the Kitaev chain to investigate the topological quantum phase transition (TQPT) in the one-dimensional spinless p-wave superconductor. Studying the behaviour of local compressibility and ground-state fidelity, show that the TQPT is signalled by the maximum of local compressibility at the quantum critical point tuned by the chemical potential. Moreover, a sudden drop of the ground-state fidelity and the divergence of fidelity susceptibility at the topological quantum critical point are used as proper indicators for the TQPT, which signals the appearance of Majorana fermions....
Sharif-Human movement instrumentation system (SHARIF-HMIS): Development and validation
, Article Medical Engineering and Physics ; Volume 61 , 2018 , Pages 87-94 ; 13504533 (ISSN) ; Akbari, A ; Zobeiri, O ; Rashedi, E ; Parnianpour, M ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
The interest in wearable systems among the biomedical engineering and clinical community continues to escalate as technical refinements enhance their potential use for both indoor and outdoor applications. For example, an important wearable technology known as a microelectromechanical system (MEMS) is demonstrating promising applications in the area of biomedical engineering. Accordingly, this study was designed to investigate the Sharif-Human Movement Instrumentation System (SHARIF-HMIS), consisting of inertial measurement units (IMUs), stretchable clothing, and a data logger—all of which can be used outside the controlled environment of a laboratory, thus enhancing its overall utility....
Synthesis of “L-cysteine–graphene oxide” hybrid by new methods and elucidation of its uptake properties for Hg(II) ion
, Article Separation Science and Technology (Philadelphia) ; Volume 53, Issue 6 , 2018 , Pages 843-855 ; 01496395 (ISSN) ; Outokesh, M ; Akbari, A ; Kosari, M ; Tayyebi, A ; Sharif University of Technology
Taylor and Francis Inc
2018
Abstract
This study introduces two new, simple, and scalable methods for synthesis of “cysteine–graphene oxide” hybrid, namely nucleophilic and covalent methods. Produced adsorbents could uptake 500 and 600 mg Hg2+/g, respectively, which are larger than capacities of most of the commercial adsorbents. By means of different instrumental techniques, chemical structures of the obtained graphene products were disclosed, and two pertinent mechanisms for their formations were suggested. Time for attaining uptake equilibrium for nucleophilic/covalent samples was 30 min/150 min, and kinetics was controlled by liquid film resistance/chemical reaction mechanisms, respectively. High selectivity and good...
Hexagonal core–shell SiO2[–MOYI]Cl–]Ag nanoframeworks for efficient photodegradation of the environmental pollutants and pathogenic bacteria
, Article Journal of Inorganic and Organometallic Polymers and Materials ; Volume 29, Issue 4 , 2019 , Pages 1314-1323 ; 15741443 (ISSN) ; Asgarpour, F ; Akbari, A ; Eftekhari Sis, B ; Lammel, G ; Sharif University of Technology
Springer New York LLC
2019
Abstract
Hexagonal core–shell SiO2[–MOYI]Cl–]Ag nanoframeworks were synthesized via surface modification of hexagonal silica nanoparticles prepared from perlite (EP) as a cheap and abundant raw material. The prepared samples were well characterized by X-ray diffraction powder (XRD), energy dispersive X-ray (EDX), diffuse reflectance spectroscopy (DRS), Brunauer–Emmett–Teller (BET) specific surface area analysis, fourier transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM). The XRD patterns confirmed that Ag and AgCl crystalline phases were successfully loaded on the surface. The TEM images were also implied that the...
Supramolecular self-assembly of oleylamide into organogels and hydrogels: a simple approach in phase selective gelation of oil spills
, Article Soft Materials ; Volume 18, Issue 1 , 2020 , Pages 55-66 ; Bagheri, A ; Younesi Araghi, H ; Akbari, A ; F. Paige, M ; Sharif University of Technology
Taylor and Francis Inc
2020
Abstract
A new gelator based of oleylamide has been introduced, which was gelled nonpolar hydrocarbon and CCl4 solvents through self-assembly. Also, the gelator formed a two-component hydrogel in combination with SDS, an anionic surfactant. UV-Vis studies revealed that the H-type and J-type aggregation of organogels in hexane and hydrogel in water, respectively. The xerogel, obtained by evaporating the solvent of organogel, selectively gelled and adsorbed oil spills on water surfaces. The effect of the various parameters, including temperature, water acidity and pH on the oil spill adsorption was studied, revealing the high ability of the xerogel to removing the oil contamination from water in up to...
Ferrofluid droplet breakup process and neck evolution under steady and pulse-width modulated magnetic fields
, Article Journal of Molecular Liquids ; Volume 343 , 2021 ; 01677322 (ISSN) ; Favakeh, A ; Mohammadi, K ; Akbari, A ; Shafii, M. B ; Sharif University of Technology
Elsevier B.V
2021
Abstract
Numerous applications in engineering and biotechnology have attracted the attention of many researchers to the analysis of underlying physical phenomena during the droplet pinch-off. In this study, the neck evolution during the formation of a ferrofluid droplet from a capillary is investigated under two types of magnetic field for a drop-on-demand system. The two types are steady and Pulse-Width Modulated (PWM) magnetic fields. First, under steady magnetic field, the necking process is studied for different values of magnetic Bond number and various angles between magnetic coil centerline and gravity. Subsequently, self-similar behavior in the vicinity of the detachment moment is observed....
Experimental and finite element prediction of bursting pressure in compound cylinders
, Article International Journal of Pressure Vessels and Piping ; Volume 81, Issue 12 , 2004 , Pages 889-896 ; 03080161 (ISSN) ; Farrahi, G. H ; Pipelzadeh, M. K ; Akbari, A ; Sharif University of Technology
Elsevier BV
2004
Abstract
Aluminium cylinders with a constant ratio of outer to inner radii, k=2.2, with different diametral interferences and various shrinkage radii were subjected to bursting and autofrettage pressures. Numerical simulations of the compound cylinders were also performed using the finite element code, NISA. The results can predict the optimum shrinkage radius to a reasonable accuracy with the use of finite element analysis. This radius corresponds to the situation when the maximum von-Mises stress at the internal radii of both the inner and outer cylinders become equal. It was shown that the maximum von-Mises stress across the wall of the cylinder is at the minimum at this shrinkage radius. The...
Sharif-human movement instrumentation system (SHARIF-HMIS) for daily activities
, Article 2012 19th Iranian Conference of Biomedical Engineering, ICBME 2012, 20 December 2012 through 21 December 2012 ; 2012 , Pages 143-148 ; 9781467331302 (ISBN) ; Zobeiri, O ; Akbari, A ; Milani, Y ; Narimani, R ; Moshiri, B ; Parnianpour, M ; Sharif University of Technology
2012
Abstract
Wearable measuring system has major effects on biomechanics of human movements especially in daily activities in order to monitor and analyze the human movements to achieve the most important kinematics parameters. In the recent decade, inertial sensors were utilized by researchers in order to developing wearable system for instrumentation of human movements. In this study, Sharif-Human Movement Instrumentation System (SHARIF-HMIS) was designed and manufactured. The system consists of inertial measurement units (IMUs), stretchable clothing and data logger. The IMU sensors are installed on the human body. The system can be used at home and also industrial environments. The main features of...
A method to capture and de-noise partial discharge pulses using discrete wavelet transform and ANFIS
, Article International Transactions on Electrical Energy Systems ; Volume 25, Issue 11 , September , 2015 , Pages 2696-2712 ; 20507038 (ISSN) ; Hajipour, E ; Vakilian, M ; Akbari, A ; Blackburn, T ; Phung, B. T ; Sharif University of Technology
John Wiley and Sons Ltd
2015
Abstract
Due to the presence of excessive noise in the recorded partial discharge (PD) current signals, de-noising of these signals is a crucial task for performing any investigation on the subject. Meanwhile, to accelerate this de-noising process a single PD pulse can be extracted from the train of those recorded pulses, followed by its de-noising. In this paper a single PD pulse is extracted from the train of recorded PD pulses, using noisy recorded data cumulative energy. A de-noising technique based on adaptive neuro-fuzzy inference systems is proposed. To verify the validity of the proposed method, four different sources of PD signals are physically simulated. The proposed method is applied on...
Voltammetric determination of dopamine at the surface of TiO2 nanoparticles modified carbon paste electrode
, Article International Journal of Electrochemical Science ; Volume 5, Issue 1 , 2010 , Pages 147-157 ; 14523981 (ISSN) ; Rajabi, H ; Beitollahi, H ; Mirjalili, B.B.F ; Akbari, A ; Taghavinia, N ; Sharif University of Technology
2010
Abstract
In the present paper, the use of a novel carbon paste electrode modified by N,N'(2,3-dihydroxybenzylidene)-1,4-phenylenediamine (DHBPD) and TiO2 nanoparticles prepared by a simple and rapid method for the determination of dopamine (DA) was described. In the first part of the work, cyclic voltammetry was used to investigate the redox properties of this modified electrode at various solution pH values and at various scan rates. A linear segment was found with slope value of about 48 mV/pH in the pH range 2.0 -12.0. The apparent charge transfer rate constant (ks) and transfer coefficient (α) for electron transfer between DHBPD and TiO2 nanoparticles-carbon paste electrode were calculated. In...
A novel binuclear iron(III)-salicylaldazine complex; synthesis, X-ray structure and catalytic activity in sulfide oxidation
, Article Polyhedron ; Volume 183 , June , 2020 ; Bagherzadeh, M ; Amini, M ; Akbari, A ; Ellern, A ; Woo, L. K ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
A novel binuclear iron(III)-salicylaldazine complex has been synthesized and characterized by various techniques such as IR and UV–Vis spectroscopy and X-ray crystallography. The catalytic oxidation of sulfides in the presence of the aforementioned complex was explored at room temperature using urea hydrogen peroxide (UHP) as an oxidant. Effects of different reaction conditions consisting catalyst and oxidant amount, solvent effect and reaction time on the catalytic activity and selectivity in the reaction of methylphenylsulfide oxidation has been surveyed. Perfect selectivity toward sulfoxide was achieved after 15 min in CH3CN by choice of a properly optimized reaction condition. © 2020...