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mechanical-permeability
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Preparation of electrospun affinity membrane and cross flow system for dynamic removal of anionic dye from colored wastewater
, Article Fibers and Polymers ; Volume 18, Issue 12 , 2017 , Pages 2387-2399 ; 12299197 (ISSN) ; Vossoughi, M ; Mahmoodi, N. M ; Sharif University of Technology
Abstract
In this research, poly(vinyl alcohol) (PVA)/chitosan electrospun nanofibrous membrane (ENM) was prepared by electrospinning method in order to investigate its dye removal ability from colored wastewater. The morphology and average fiber diameter of the membranes were investigated by scanning electron microscopy (SEM), image analysis and atomic force microscopy (AFM). The chemical characterization was studied by Fourier transform infrared spectroscopy (FTIR). The permeability of the membranes was evaluated by measuring pure water flux (PWF). In order to investigate the performance of the prepared membranes they were used in the batch adsorption and membrane separation for dye removal from...
A flat polymeric membrane sensor for carbon dioxide/nitrogen gas mixture
, Article Chemical Engineering Communications ; Volume 204, Issue 4 , 2017 , Pages 445-452 ; 00986445 (ISSN) ; Mousavi, S. A ; Shojaei, A ; Sharif University of Technology
Taylor and Francis Ltd
2017
Abstract
A gas sensor was developed to measure the concentration of binary gas mixtures. This sensor works based on the permeability change of different gas mixtures across the polymeric membranes. Although high values of permeability and selectivity are needed for an ideal separation, the performance of this sensor mainly depends on the permeability factor. Polysulfone and silicone rubber were applied as the membrane base and coat, respectively. Moreover, in contrast to existing polymeric sensors that use hollow fibers, the present sensor is made of flat membranes. This new design is cheaper, smaller, and easier to use in comparison to the hollow fiber polymeric sensors. In order to test the sensor...
Investigating the permeability–porosity relation of percolation-based porous media using the lattice boltzmann method
, Article Journal of Porous Media ; Volume 20, Issue 10 , 2017 , Pages 899-919 ; 1091028X (ISSN) ; Masihi, M ; Jamshidi, S ; Pishvaie, M. R ; Sharif University of Technology
Abstract
The semi-empirical Kozeny–Carman (KC) equation is the widely used equation for determining permeability of porous media. Recent studies have shown that KC coefficient (CKC ) is a function of porous media parameters. In this study, the relation between parameters of randomly generated porous media is investigated to improve permeability prediction. In particular, site percolation theory is applied to construct random porous media. The static parameters of porous media, including porosity and specific surface area, are evaluated from porous media structure, and dynamic parameters, tortuosity and permeability, are derived from the results of Lattice Boltzmann fluid flow simulation....
Enhancement of surface properties and performance of reverse osmosis membranes after surface modification: a review
, Article Desalination ; Volume 420 , 2017 , Pages 330-383 ; 00119164 (ISSN) ; Bastani, D ; Musavi, S. A ; Sharif University of Technology
Abstract
Reverse osmosis (RO) membrane process has become the most promising technology for desalination to produce purified water. Among numerous polymeric materials used to fabricate RO membranes, aromatic polyamide thin film composite (TFC) membranes are dominant in commercial RO membrane processes because of their high salt rejection and water permeability as well as their excellent chemical, thermal, and mechanical stability. However, the major hindrance to the effective application of polyamide TFC RO membranes is membrane fouling. Furthermore, polyamide TFC RO membranes have limited stability to chlorine, which is commonly used as disinfect to control membrane biofouling. These two factors...
Dynamic modeling of the formation damage and mud cake deposition using filtration theories coupled with SEM image processing
, Article Journal of Natural Gas Science and Engineering ; Volume 42 , 2017 , Pages 157-168 ; 18755100 (ISSN) ; Salehi, S ; Sharif University of Technology
Elsevier B.V
2017
Abstract
In the present paper, a dynamic modeling is presented for deposition of the mud solid particles over and through the porous sandstones during permeability plugging experiments. Scanning electron microscopy (SEM) coupled with image processing are utilized to find the porosity and pore size distribution of the mud cake. The structure of the porous rock as well as the mud cake are modeled via bundle of the curved tubes approach and deposition probability of the solid particles has been taken into the account through filtration theories. Four different sandstones in addition to four mud samples were utilized to measure and predict the volume of the expelled fluid during the 30 min of filtration...
Estimation of carbonates permeability using pore network parameters extracted from thin section images and comparison with experimental data
, Article Journal of Natural Gas Science and Engineering ; Volume 42 , 2017 , Pages 85-98 ; 18755100 (ISSN) ; Assadi, A ; Kharrat, R ; Dashti, N ; Ayatollahi, S ; Sharif University of Technology
Elsevier B.V
2017
Abstract
Petrography and image analysis have been widely used to identify and quantify porous characteristics in carbonate reservoirs. This paper uses the thin section images of 200 carbonate rock samples to predict the absolute permeability using intelligent and empirical methods. For each thin section, several pore network parameters are extracted from thin section images of rocks including the average pore size, average throat size, average throat length and average 2-D coordination number of pore network. A neural-based model successfully predicts the permeability of samples using pore network parameters as the inputs. Second neural network is applied for predicting absolute permeability...
Pore-scale modeling of rarefied gas flow in fractal micro-porous media, using lattice Boltzmann method (LBM)
, Article Journal of Thermal Analysis and Calorimetry ; 2019 , Pages 1-12 ; 13886150 (ISSN) ; Salimi, M. R ; Taeibi Rahni, M ; Sharif University of Technology
Springer Netherlands
2019
Abstract
Due to the widespread use of rarefied gas flow in micro-porous media in industrial and engineering problems, a pore-scale modeling of rarefied gas flow through two micro-porous media with fractal geometries is presented, using lattice Boltzmann method. For this purpose, square- and circular-based Sierpinski carpets with fractal geometries are selected due to their inherent behavior for real porous media. Diffusive reflection slip model is used and developed for these porous media through this study. With this respect, the planar Poiseuille flow is selected as a benchmark and validated with the literature. The effect of Knudsen number (Kn) on the permeability is investigated and compared in...
Pore structure evolution during sintering of HDPE particles
, Article Polymer ; Volume 183 , 2019 ; 00323861 (ISSN) ; Pircheraghi, G ; Foudazi, R ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
Sintering is a processing technique in which loose particles consolidate at elevated temperatures to form porous monoliths. Sintering is also a critical stage in recent additive manufacturing method like selective laser sintering. In this study, using an affordable alternative to X-ray tomography technique, we analyze the pore structure evolution in sintered parts made of nascent high-density polyethylene (HDPE) particles in terms of pore surface genus and pore surface curvature. Also, we investigate the underlying microstructural development and macroscopic properties of sintered parts. It is observed that pore structure and macroscopic permeability are strongly influenced by the...
Optimum rice husk ash content and bacterial concentration in self-compacting concrete
, Article Construction and Building Materials ; Volume 222 , 2019 , Pages 796-813 ; 09500618 (ISSN) ; Shoaei, P ; Bahrami, N ; Vaezi, M ; Ozbakkaloglu, T ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
This study is aimed at optimizing the rice husk ash (RHA) content and bacterial concentration in self-compacting concrete (SCC). For this purpose, cement was partially replaced with RHA at 0%, 5%, 10%, 15%, 20%, 25%, and 30% by weight of cement. In addition, micro-silica (MS) was added to all mixes at a dosage of 10% by weight of cementitious materials. The mix with the optimum RHA content was supplied with bacterial cells with concentrations of 103, 105, and 107 cells/ml to reduce the formation of micro-cracks. The RHA concretes showed reduced workability with increasing RHA content. Energy-dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM) analyses were performed on...
Analyzing and predicting permeability coefficient of roller-compacted concrete (RCC)
, Article Journal of Testing and Evaluation ; Volume 49, Issue 3 , 2019 ; 00903973 (ISSN) ; Toufigh, V ; Ghaemian, M ; Sharif University of Technology
ASTM International
2019
Abstract
The permeability of roller-compacted concrete (RCC) substantially affects its functionality and safety. This study investigates the effect of mix design parameters on the performance of RCC. For this purpose, approximately 500 laboratory specimens were prepared and tested. A formula and an artificial neural network (ANN) were proposed to predict the permeability coefficient of RCC by considering the main parameters, which were then verified independently using new specimens. Furthermore, the experimental data were analyzed by the Taguchi method and analysis of variance (ANOVA) to evaluate the level of parameter contribution. Based on the results, the permeability coefficient was highly...
Geochemical and hydrodynamic modeling of permeability impairment due to composite scale formation in porous media
, Article Journal of Petroleum Science and Engineering ; Volume 176 , 2019 , Pages 1071-1081 ; 09204105 (ISSN) ; Kalantariasl, A ; Parvazdavani, M ; Abbasi, S ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Injectivity decline due to mineral scale deposition in near wellbore region of water injection wells is one of the main challenging issues and have been widely reported in the literature. One of the main mechanisms of injectivity loss is incompatibility between injected and formation waters that may result in inorganic scale precipitation and subsequent deposition in porous media. Reliable reactive flow models to predict type and amount of scale along with permeability decline estimation allow planning and risk management of water flood projects. In this paper, we present a coupled geochemical and hydrodynamic model to simulate the scale precipitation and deposition of mineral scales in...
Experimental study of the effect of water to cement ratio on mechanical and durability properties of Nano-silica concretes with Polypropylene fibers
, Article Scientia Iranica ; Volume 26, Issue 5 A , 2019 , Pages 1-18 ; 10263098 (ISSN) ; Ghaemian, M ; Hosseini, S. A ; Sharif University of Technology
Sharif University of Technology
2019
Abstract
In the present paper, the effect of Nano silica on mechanical properties and durability of concrete containing polypropylene fibers has been investigated. Here, the length and length to diameter ratio of used polypropylene fibers were considered to be fixed and equal to 18 mm and 600 respectively and the cement content was 479 kg/m3. The effect of fibers and Nano silica in four different percentages for each one at 0.1, 0.2, 0.3 and 0.4 percent by volume for fibers and 3 percent for Nano silica in concrete with water to cement ratio of 0.33, 0.36, 0.4, 0.44 and 0.5 have been compared and evaluated. In total, more than 425 cubic and cylindrical specimens were made according to ASTM standards....
Optimal design of flux diverter using genetic algorithm for axial short circuit force reduction in HTS transformers
, Article IEEE Transactions on Applied Superconductivity ; Volume 30, Issue 1 , January , 2020 ; Vakilian, M ; Hekmati, A ; Fardmanesh, M ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2020
Abstract
The appealing advantages of high-temperature superconducting (HTS) power transformers over conventional ones have attracted transformer manufacturing companies, power companies, research institutes, and universities worldwide to conduct research and development in this field. Unfortunately, HTS transformers are more vulnerable to mechanical stresses than conventional transformers. The results of the interaction between current carrying windings and leakage magnetic fluxes are the electromagnetic forces, which act on transformer windings. Under short circuit events, these forces are remarkable, and, therefore, catastrophic failure of transformer may arise. Flux-diverter applications have been...
Microstructural, thermal, electrical, and magnetic properties of optimized Fe3O4–SiC hybrid nano filler reinforced aluminium matrix composite
, Article Materials Chemistry and Physics ; Volume 258 , 2021 ; 02540584 (ISSN) ; Ariff, A. H. M ; Sarraf, M ; Sulaiman, S ; Hong, T. S ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
In the present study, the hybrid reinforcements (Fe3O4–SiC) novel composite has been successfully fabricated by powder metallurgy method. Adding Fe3O4 nanoparticles and SiC hybrid reinforcements in the aluminium matrix, improved the magnetic permeability of aluminium matrix composites as well as, thermal properties without mechanical degradation. In this study, the aim was to define the influence of SiC–Fe3O4 nanoparticles on microstructural, thermal, electrical, and magnetic properties of the composite. Based on obtained results, the highest density and hardness is 2.72 g/cm3 and 93 HV respectively. Adding (10–30 wt% SiC) into Al–15Fe3O4 slightly improved the magnetic saturation from...
simulation of thermo-hydro-mechanical processes at Soultz-sous-Forêts
, Article Energies ; Volume 15, Issue 24 , 2022 ; 19961073 (ISSN) ; Singh, M ; Mahyapour, R ; Tangirala, S. K ; Bär, K ; Sass, I ; Sharif University of Technology
MDPI
2022
Abstract
Porosity and permeability alteration due to the thermo-poro-elastic stress field disturbance from the cold fluid injection is a deciding factor for longer, more economic, and safer heat extraction from an enhanced geothermal system (EGS). In the Soultz-sous-Forêts geothermal system, faulted zones are the main flow paths, and the resulting porosity–permeability development over time due to stress reorientation is more sensitive in comparison with the regions without faulted zones. Available operational and field data are combined through a validated numerical simulation model to examine the mechanical impact on the pressure and temperature evolution. Results shows that near the injection...
Genetic algorithm-based pore network extraction from micro-computed tomography images
, Article Chemical Engineering Science ; Volume 92 , 2013 , Pages 157-166 ; 00092509 (ISSN) ; Jamshidi, S ; Iglauer, S ; Boozarjomehry, R ; Sharif University of Technology
2013
Abstract
A genetic-based pore network extraction method from micro-computed tomography (micro-CT) images is proposed in this paper. Several variables such as the number, radius and location of pores, the coordination number, as well as the radius and length of the throats are used herein as the optimization parameters. Two approaches to generate the pore network structure are presented. Unlike previous algorithms, the presented approaches are directly based on minimizing the error between the extracted network and the real porous medium. This leads to the generation of more accurate results while reducing required computational memories. Two different objective functions are used in building the...
Dynamic responses of intervertebral disc during static creep and dynamic cyclic loading: A parametric Poroelastic finite element analysis
, Article Biomedical Engineering - Applications, Basis and Communications ; Volume 25, Issue 1 , 2013 ; 10162372 (ISSN) ; Haghpanahi, M ; Parnianpour, M ; Wang, J. L ; Sharif University of Technology
2013
Abstract
Low back pain is a common reason for activity limitation in people younger than 45 years old, and was proved to be associated with heavy physical works, repetitive lifting, impact, stationary work postures and vibrations. The study of load transferring and the loading condition encountered in spinal column can be simulated by finite element models. The intervertebral disc is a structure composed of a porous material. Many physical models were developed to simulate this phenomenon. The confounding effects of poroelastic properties and loading conditions on disc mechanical responses are, nevertheless, not cleared yet. The objective of this study was to develop an axisymmetric poroelastic...
Investigation on asphaltene deposition mechanisms during CO2 flooding processes in porous media: A novel experimental study and a modified model based on multilayer theory for asphaltene adsorption
, Article Energy and Fuels ; Volume 26, Issue 8 , 2012 , Pages 5080-5091 ; 08870624 (ISSN) ; Ghotbi, C ; Taghikhani, V ; Shahrabadi, A ; Sharif University of Technology
2012
Abstract
In this paper, oil recovery and permeability reduction of a tight sandstone core sample in miscible CO2 flooding processes due to asphaltene deposition were studied using an Iranian bottom hole live oil sample in order to distinguish between the mechanical plugging and adsorption mechanisms of asphaltene involved in the interfacial interaction of the asphaltene/mineral rock system. A novel experimental method was designed and proposed to measure the amount of deposited asphaltene due to different mechanisms using the cyclohexane or toluene reverse flooding and spectrophotometer. In this work, the bottom hole live oil sample was injected first to a long core and then CO 2 injection was...
Pareto-based robust optimization of water-flooding using multiple realizations
, Article Journal of Petroleum Science and Engineering ; Volume 132 , 2015 , Pages 18-27 ; 09204105 (ISSN) ; Pishvaie, M. R ; Sharif University of Technology
Elsevier
2015
Abstract
Robust optimization (RO) approach is inherently a multi-objective paradigm. The proposed multi-objective optimization formulation would attempt to find the optimum - yet robust - water injection policies. Two multi-objective, Pareto-based robust optimization scenarios have been investigated to encounter the permeability uncertainties. These multi-objective RO scenarios have been done based on a small representative set of realizations but they have introduced optimum points that could be reliable for the original set of realizations either. In both scenarios, the desired objective functions are expected value and variance of Net Present Value (NPV). The underlying RO scenarios have been done...
Pore-scale simulation of fluid flow passing over a porously covered square cylinder located at the middle of a channel, using a hybrid MRT-LBM–FVM approach
, Article Theoretical and Computational Fluid Dynamics ; Volume 29, Issue 3 , 2015 , Pages 171-191 ; 09354964 (ISSN) ; Taeibi Rahni, M ; Jam, F ; Sharif University of Technology
Springer New York LLC
2015
Abstract
A comprehensive study was performed to analyze the unsteady laminar flow characteristics around a porously covered, a fully porous, and a solid squared section cylinder located in the middle of a plane channel. In order to simulate fluid flow inside porous media and porous–fluid interface accurately (minimizing modeling error), the porous region was analyzed in pore scale, using LBM. Additionally, to minimize the LBM-related compressibility error through the porous region, a multi-block multiple relaxation time lattice Boltzmann method (MRT-LBM) was used. Also, to decrease CPU time, a Navier–Stokes flow solver, based on finite volume method and SIMPLE algorithm, was coupled with MRT-LBM to...