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zarenezhad--b
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Performance evaluation of a new nanocomposite polymer gel for water shutoff in petroleum reservoirs
, Article Journal of Dispersion Science and Technology ; 2018 ; 01932691 (ISSN) ; Ayatollahi, S ; ZareNezhad, B ; Sharif University of Technology
Taylor and Francis Inc
2018
Abstract
A new polymer gel nanocomposite is fabricated for excess water production control (water shut off) in petroleum reservoirs and its rheological behavior is evaluated in the presence of sea water and formation water at the temperature of 100 °C. It is shown that at a high salinity without using SiO2 nanoparticles, the elastic modulus of synthesized polymer gel in the presence of sea water and formation water are 12.5 Pa and 9.8 Pa respectively. However by incorporation of SiO2 nanoparticles in the polymer gel matrix, the elastic modulus of synthesized polymer gel in the presence of sea water and formation water can be improved to 13.56 Pa and 11.57 Pa respectively, which is quite interesting...
Performance evaluation of a new nanocomposite polymer gel for water shutoff in petroleum reservoirs
, Article Journal of Dispersion Science and Technology ; Volume 40, Issue 10 , 2019 , Pages 1479-1487 ; 01932691 (ISSN) ; Ayatollahi, S ; ZareNezhad, B ; Sharif University of Technology
Taylor and Francis Inc
2019
Abstract
A new polymer gel nanocomposite is fabricated for excess water production control (water shut off) in petroleum reservoirs and its rheological behavior is evaluated in the presence of sea water and formation water at the temperature of 100 °C. It is shown that at a high salinity without using SiO2 nanoparticles, the elastic modulus of synthesized polymer gel in the presence of sea water and formation water are 12.5 Pa and 9.8 Pa respectively. However by incorporation of SiO2 nanoparticles in the polymer gel matrix, the elastic modulus of synthesized polymer gel in the presence of sea water and formation water can be improved to 13.56 Pa and 11.57 Pa respectively, which is quite interesting...
Fabrication of a highly efficient new nanocomposite polymer gel for controlling the excess water production in petroleum reservoirs and increasing the performance of enhanced oil recovery processes
, Article Chinese Journal of Chemical Engineering ; Volume 32 , 2021 , Pages 385-392 ; 10049541 (ISSN) ; Ayatollahi, S ; ZareNezhad, B ; Sharif University of Technology
Materials China
2021
Abstract
A new nanocomposite polymer gel is synthesized for reduction of excess water production in petroleum reservoirs at real operating conditions. This new nanocomposite gel contains SiO2 nanoparticles, partially hydrolyzed polyacrylamide (HPAM) and chromium triacetate. High pressure and high temperature tests using porous carbonate core are carried out to evaluate the effects of nanoparticles on the synthesized polymer gel performance. It is shown that the residual resistance factor ratio of water to oil using the synthesized polymer gel nanocomposite in this work is much higher than that of the ordinary polymer gels. The presented results confirm the high performance of the synthesized...
Nanofluid-assisted gas to hydrate (GTH) energy conversion for promoting CO 2 recovery and sequestration processes in the petroleum industry
, Article Petroleum Science and Technology ; Volume 34, Issue 1 , 2016 , Pages 37-43 ; 10916466 (ISSN) ; Montazeri, V ; Sharif University of Technology
Taylor and Francis Inc
2016
Abstract
In this work the enhancement of gas to hydrate conversion employing the nanographene oxide (NGO)-based nanofluid regarding CO2 capture and sequestration recovery is investigated. A new series of experiments are carried out at different pressures, temperatures, agitation intensities and NGO promoter concentrations by using a newly developed fully automated GTH (gas to hydrate) energy converter. According to the presented results at the 3 MPa and 275.15 K and in the presence of 30 ppm NGO, it is possible to reach a CO2 gas to hydrate conversion of 95% at a low impeller speed in less than 2.5 h, which is quite interesting from an energy consumption standpoint. The presented approach can have...
Improvement of Perovskite Coating to Increase Operation Efficiency of Photovoltaic Cells
, Ph.D. Dissertation Sharif University of Technology ; Askari, Masoud (Supervisor) ; Halali, Mohammad (Supervisor)
Abstract
In this work, polyvinylidene difluoride (PVDF) as a ferroelectric polymer, polyaniline (PANI) and polypyrrole (PPy) as conductive polymer additives are used to fabricate high performance mesoporous CH3NH3PbI3-xClx mixed-halide perovskite solar cells in a sequential deposition method. Using polymer additives in perovskite precursor solution leads to modification of perovskite layer morphology by changing nucleation and growth of perovskite grains. Besides, conductive polymer additives in perovskite layer help to more charge carrier transfer. Power conversion efficiency has been enhanced from 10.40 % to 16.51% and to 13.21 % in ambient atmosphere in the presence of 1.0 wt. % of PVDF and PPy...
Efficient carrier utilization induced by conductive polypyrrole additives in organic-inorganic halide perovskite solar cells
, Article Solar Energy ; Volume 207 , 2020 , Pages 1300-1307 ; Balkan, T ; Solati, N ; Halali, M ; Askari, M ; Kaya, S ; Sharif University of Technology
Elsevier Ltd
2020
Abstract
The morphology of the perovskite layer, the effective extraction of the charge carriers, and their transport are the main factors determining the power conversion efficiency (PCE) of the perovskite solar cells (PSCs). In this work, we demonstrated that the geometric and electronic structures of the PSCs could be modified by using a conductive polymer additive in the lead (Pb) halide layer prepared by a two-step deposition method. Polypyrrole (PPy) as a conductive polymer is used in the perovskite layers which could increase the PCE of CH3NH3PbI3-xClx mixed-halide PSCs. By adding an optimized amount of PPy, PCE has been raised from 10.4 to 13.2%. PPy acts as a conductive channel facilitating...
Enhanced electron transport induced by a ferroelectric field in efficient halide perovskite solar cells
, Article Solar Energy Materials and Solar Cells ; Volume 206 , 2020 ; Askari, M ; Halali, M ; Solati, N ; Balkan, T ; Kaya, S ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Perovskite solar cells have been appearing as a superior photovoltaic device owing to their high photovoltaic performance and low cost of fabrication. The formation of a compact and uniform perovskite layer with large crystal size is a significant factor to get the best device performance. In this work, polyvinylidene difluoride (PVDF) was used as a ferroelectric polymer additive to fabricate high-performance mesoporous CH3NH3PbI3-xClx mixed-halide perovskite solar cells in a sequential deposition method. Power conversion efficiency has been enhanced from 10.4 to 16.51% in an ambient atmosphere in the presence of an optimized amount of PVDF assuring continuous and smooth layers with large...
Experimental Study of Effect of Nano-graphen Oxide on Methane Hydrate Formation Rate and Storage Capacity
, M.Sc. Thesis Sharif University of Technology ; Baghalha, Morteza (Supervisor) ; Ramazani, Ahmad (Supervisor) ; Zarenezhad, Bahman (Co-Advisor)
Abstract
According to the importance of conversion and transmission of energy, and introduction of hydrate formation process as an alternative method, in this study, the nano-graphene oxide is used to increase the rate if methane gas hydrates formation. The experiments were performed at different concentrations of 30 to 70 ppm and the results were compared with pure water. The effect of temperature and pressure on hydrate formation at temperatures of 1 and 2˚C and pressures of 48 and 53 bar were studied. And it was found that nano-graphene oxide can be used to accelerate the methane hydrates formation. The effect of ultrasonic on methane hydrate formation has been studied that it was found that the...
Investigation on Effects of Nanoparticles Presence on Hydrate Formation Characterization During Drilling
, M.Sc. Thesis Sharif University of Technology ; Mohammadi, Ali Asghar (Supervisor) ; Zarenezhad, Bahman (Co-Advisor) ; Ramazani, Ahmad (Co-Advisor)
Abstract
In past two decades, the direction of oil and gas exploration has moved towards deep water drilling. The pressure and temperature in these zones are ideal for gas hydrate formation that can cause serious and sometimes uncontrollable issues during drilling operations. Gas hydrate formation while drilling can cause problems such as occurrence of kick and blowout, plug chock and kill line, and change in rheology of drilling mud. On the other hand, nowadays, nanotechnology has created an evolution in engineering sciences and because of the wide range of this science, drilling industry is affected like other industries. In the meantime, because of high yield, high stability and various methods of...
Microwave-induced Cannizzaro reaction over neutral γ-alumina as a polymeric catalyst [electronic resource]
, Article Reactive and Functional Polymers ; 01/2002; 51(1):49-53 ; Soleimanzadeh, B ; Marandi, G. B
Abstract
γ-Alumina is used to catalyze the Cannizzaro reaction in the absence of any base under microwave irradiation in high yields. In the case of terephthalaldehyde the reaction is carried out with high selectivity
SnCl4/SiO2: an efficient heterogeneous alternative for one-pot synthesis of β-acetamidoketones
, Article Journal of the Chinese Chemical Society ; Volume 56, Issue 2 , 2009 , Pages 386-391 ; 00094536 (ISSN) ; Mahmoodi Hashemi, M ; Sadeghi, B ; Emtiazi, H ; Sharif University of Technology
2009
Abstract
Enolizable ketones have been reacted in a one-pot method with aromatic aldehydes, acetyl chloride and acetonitrile at room temperature in the presence of SnCl4/SiO2 to furnish the corresponding β-acetamidoketones in improved yields. Acetylation of an aromatic hydroxyl group was observed while using 4-hydroxybenzaldehyde or vanillin and the corresponding β-acetamidoketones were isolated in an excellent yield
Turbulent flow in converging nozzles, part one: Boundary layer solution
, Article Applied Mathematics and Mechanics (English Edition) ; Volume 32, Issue 5 , 2011 , Pages 645-662 ; 02534827 (ISSN) ; Farhanieh, B ; Firoozabadi, B ; Sharif University of Technology
2011
Abstract
The boundary layer integral method is used to investigate the development of the turbulent swirling flow at the entrance region of a conical nozzle. The governing equations in the spherical coordinate system are simplified with the boundary layer assumptions and integrated through the boundary layer. The resulting sets of differential equations are then solved by the fourth-order Adams predictor-corrector method. The free vortex and uniform velocity profiles are applied for the tangential and axial velocities at the inlet region, respectively. Due to the lack of experimental data for swirling flows in converging nozzles, the developed model is validated against the numerical simulations. The...
Numerical investigation of steady density currents flowing down an incline using v2̄ - F turbulence model
, Article Journal of Fluids Engineering, Transactions of the ASME ; Volume 129, Issue 9 , 2007 , Pages 1172-1178 ; 00982202 (ISSN) ; Firoozabadi, B ; Farhanieh, B ; Sharif University of Technology
2007
Abstract
The governing equations of two-dimensional steady density currents are solved numerically using a finite volume method. The v2̄-f turbulence model, based on standard k - s model, is used for the turbulence closure. In this method, all Reynolds stress equations are replaced with both a transport equation for v2̄ and an elliptic relaxation equation for f, a parameter closely related to the pressure strain redistribution term. The Simple-C procedure is used for pressure-velocity coupling. In addition, Boussinesq's approximation is used to obtain the momentum equation. The computed height of the progressive density current is compared to the measured data in the literature, resulting in good...
Numerical simulation of turbid-density current using v2̄ - f turbulence model
, Article 2005 ASME International Mechanical Engineering Congress and Exposition, IMECE 2005, Orlando, FL, 5 November 2005 through 11 November 2005 ; Volume 261 FED , 2005 , Pages 619-627 ; 08888116 (ISSN); 0791842193 (ISBN); 9780791842195 (ISBN) ; Firoozabadi, B ; Farhanieh, B ; Sharif University of Technology
2005
Abstract
The deposition behavior of fine sediment is an important phenomenon, and yet unclear to engineers concerned about reservoir sedimentation. An elliptic relaxation turbulence model (v2̄ - f model) has been used to simulate the motion of turbid density currents laden whit fine solid particles. During the last few years, the v2̄ - f turbulence model has become increasingly popular due to its ability to account for near-wall damping without use of damping functions. In addition, it has been proved that the v2̄ - f model to be superior to other RANS methods in many fluid flows where complex flow features are present. Due to low Reynolds number turbulence of turbidity current,(its critical Reynolds...
Analytical solution for creeping motion of a viscoelastic drop falling through a Newtonian fluid
, Article Korea Australia Rheology Journal ; Vol. 26, issue. 1 , 2014 , pp. 91-104 ; ISSN: 1226119X ; Norouzi, M ; Firoozabadi, B ; Sharif University of Technology
2014
Abstract
In this paper, an analytical solution for steady creeping motion of viscoelastic drop falling through a viscous Newtonian fluid is presented. The Oldroyd-B model is used as the constitutive equation. The analytical solutions for both interior and exterior flows are obtained using the perturbation method. Deborah number and capillary numbers are considered as the perturbation parameters. The effect of viscoelastic properties on drop shape and motion are studied in detail. The previous empirical studies indicated that unlike the Newtonian creeping drop in which the drop shape is exactly spherical, a dimpled shape appears in viscoelastic drops. It is shown that the results of the present...
Theoretical and experimental study on the motion and shape of viscoelastic falling drops through Newtonian media
, Article Rheologica Acta ; Volume 55, Issue 11-12 , 2016 , Pages 935-955 ; 00354511 (ISSN) ; Norouzi, M ; Firoozabadi, B ; Sharif University of Technology
Springer Verlag
2016
Abstract
In this paper, creeping motion of a viscoelastic drop falling through a Newtonian fluid is investigated experimentally and analytically. A polymeric solution of 0.08 % xanthan gum in 80:20 glycerol/water and silicon oil is implemented as the viscoelastic drop and the bulk viscous fluids, respectively. The shape and motion of falling drops are visualized using a high speed camera. The perturbation technique is employed for both interior and exterior flows, and Deborah and capillary numbers are considered as perturbation parameters up to second order. The product of Deborah and capillary numbers is also used as a perturbation parameter to apply the boundary condition on the deformation on the...
Minimizing uplink delay in delay-sensitive 5G CRAN platforms
, Article 2nd IEEE 5G World Forum, 5GWF 2019, 30 September 2019 through 2 October 2019 ; 2019 , Pages 154-160 ; 9781728136271 (ISBN) ; Kanaanian, B ; Khalaj, B. H ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
In this paper, we consider the problem of minimizing the uplink delays of users in a 5G cellular network. Such cellular network is based on a Cloud Radio Access Network (CRAN) architecture with limited fronthaul capacity, where our goal is to minimize delays of all users through an optimal resource allocation. Earlier works minimize average delay of each user assuming same transmit power for all users. Combining Pareto optimization and Markov Decision Process (MDP), we show that every desired balance in the trade-off among infinite-horizon average-reward delays, is achievable by minimizing a properly weighted sum delays. In addition, we solve the problem in two realistic scenarios;...
Microwave-induced Cannizzaro reaction over neutral γ-alumina as a polymeric catalyst
, Article Reactive and Functional Polymers ; Volume 51, Issue 1 , 2002 , Pages 49-53 ; 13815148 (ISSN) ; Soleimanzadeh, B ; Marandi, G. B ; Sharif University of Technology
2002
Abstract
Microwave induced Cannizzaro reaction, which was performed in presence of neutral γ-alumina as a polymeric catalyst, was discussed. Cannizzaro reaction was carried out on alumina surface and other unknown products were also obtained. Solvent extraction method was utilized to isolate mild and selective benzyl alcohol and carboxylic acids
Feedback bit reduction for antenna selection methods in wireless systems
, Article 2005 13th IEEE International Conference on Networks jointly held with the 2005 7th IEEE Malaysia International Conference on Communications, Kuala Lumpur, 16 November 2005 through 18 November 2005 ; Volume 1 , 2005 , Pages 229-233 ; 1424400007 (ISBN); 9781424400003 (ISBN) ; Babadi, B ; Hossein Khalaj, B ; Sharif University of Technology
2005
Abstract
A well known method to reduce the intrinsic complexity of Multiple Input Multiple Output (MIMO) systems is to choose a subset of available antennas which have stronger links than the others, in order to perform the specified MIMO algorithm. The data resulted from the antenna selection process (at the receiver side) is sent back to the transmitter side via a feedback channel. There seems to be a need to reduce the number of feedack bits, specially when the number of antennas is not small. In this paper, we investigate the problem of reducing the number of feedback bits in antenna selection techniques. We've proposed two methods using vector quantization techniques to perform feedback bit...
A distributed locality-aware neighbor selection algorithm for P2P video streaming over wireless mesh networks
, Article 2012 6th International Symposium on Telecommunications, IST 2012 ; 2012 , Pages 639-643 ; 9781467320733 (ISBN) ; Akbari, B ; Khansari, M ; Ahmadifar, B ; Sharif University of Technology
2012
Abstract
Nowadays, deployment of peer-to-peer video streaming systems over wireless mesh networks has attained raising popularity among large number of users around the world. In this paper, we present an efficient peer-to-peer live video streaming architecture over multi-hop wireless mesh networks. In our proposed architecture, we take the physical topology of network into account and based on a distributed distributed locality-aware neighbor selection algorithm in the overlay construction phase, we generate an efficient mesh-based overlay on top of wireless mesh networks. In locality-aware neighbor selection algorithm, instead of choosing randomly, peers find their best neighbors based on their...