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Fluid Dynamics & Materials Processing 2023年第1期19卷 61-81页

作者： Muhammad Salman Kausar H.A.M.Al-sharifi Abid Hussanan Mustafa Mamat Faculty of Informatics and Computing University Sultan Zainal Abidin(Kampus Gong Badak)Kuala TerengganuTerengganuMalaysia Department of Mathematics College of Education for Pure SciencesUniversity of KerbalaKerbalaIraq Department of Mathematics Division of Science and TechnologyUniversity of EducationLahorePakistan

In this paper,the effects of thermal radiation and viscous dissipation on the stagnation–point flow of a micropolar fluid over a permeable stretching sheet with suction and injection are analyzed and discussed.A suitable similarity transformation is used to convert the governing nonlinear partial differential equations into a system of nonlinear ordinary differential equations,which are then solved numerically by a fourth–order Runge–Kutta *** is found that the linear fluid velocity decreases with the enhancement of the porosity,boundary,and suction ***,it increases with the micropolar and injection *** angular velocity grows with the boundary,porosity,and suction parameters,whereas it is reduced if the micropolar and injection parameters become *** is concluded that the thermal boundary layer extension increases with the injection parameter and decreases with the suction parameter.

关键词： Micropolar fluid viscous dissipation stagnation point stretching sheet porous media thermal radiation

Evaluation of the remaining lateral torsional buckling capacity in corroded steel members

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第11期11卷 887-897页

作者： Yasser sharifi Reza RAHGOZAR Department of Civil Engineering Kerman University

Corrosion is one of the main causes of deterioration in steel structures. Loss of thickness in flanges and web of corroded steel beams leads to reduction in section properties which can reduce the lateral torsional buckling capacity of the member. In this paper, thickness loss data were compiled from four samples of corrosion damaged I-beams removed from a petro-chemical plant. Visual examination of the four corroded beams showed that they were corroded uniformly. To improve the accuracy of the results, a large number of measurements for surface roughness were taken for each beam, totally 770 values to obtain the average thickness of flanges and web of each beam. The data was used to develop a corrosion decay model in order to calculate the percentage remaining lateral torsional buckling capacity of long and short span beams which are laterally unrestrained. To estimate the percentage of remaining lateral torsional buckling capacity in the corroded damaged I-beams, the readily available minimum curves for different types of universal beams in conjunction with information on the thickness loss were used. The results can be used by practicing engineers for better estimation on the service life of deteriorated steel structures.

关键词： Corrosion Steel structures Lateral torsional buckling Beams

Nanoparticle Shape Effect on a Sodium–Alginate Based Cu–Nanofluid under a Transverse Magnetic Field

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Fluid Dynamics & Materials Processing 2023年第7期19卷 1875-1896页

作者： Samia Rani H.A.M.Al–sharifi Mohammad S.Zannon Abid Hussanan Zafar Ullah Department of Mathematics Division of Science and TechnologyUniversity of EducationLahore54000Pakistan Department of Mathematics College of Education for Pure SciencesUniversity of KerbalaKerbala1125Iraq Department of Mathematics Faculty of ScienceTafila Technical University(TTU)Al-IessTafila66110Jordan

Sodium-alginate(SA)based nanofluids represent a new generation of fluids with improved performances in terms of heat *** work examines the influence of the nanoparticle shape on a non–Newtonian viscoplastic Cu–nanofluid pertaining to this *** particular,a stretching/shrinking sheet subjected to a transverse magnetic field is *** proposed Cu–nanofluid consists of four different nanoparticles having different shapes,namely bricks,cylinders,platelets,and blades dispersed in a mixture of sodium alginate with Prandtl number Pr=*** similarity transformations are employed to reduce non–linear PDEs into a system of ODEs and these equations and related boundary conditions are solved numerically by means of a Runge–Kutta–Fehlberg(RKF)***,analytical solutions are obtained through the application of a MAPLE built–in differential equation solver(Dsolve).The behavior of prominent parameters against velocity and temperature is *** is found that the temperature increases for all shapes of nanoparticles with the viscoplastic parameter and the Eckert number.

关键词： Nanofluid magnetic field viscous dissipation Dsolve

Stabilizing silica nanoparticles in high saline water by using polyvinylpyrrolidone for reduction of asphaltene precipitation damage under dynamic condition

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Chinese Journal of Chemical Engineering 2019年第5期27卷 1021-1029页

作者： Mohammad Reza Aghajanzadeh Mohammad sharifi Department of Petroleum Engineering Amirkabir University of Technology

In this study, the performance of stable nanofluid containing SiO2 nanoparticles dispersed and stabilized in high salinity brine for asphaltene inhibition in dynamic condition is evaluated. In the first stage of this work, the stability of silica nanoparticles in different range of water salinity(0–100000 mg·L-1) is investigated. Next, stable nanofluid containing highest salinity is selected as asphaltene inhibitor agent to inject into the damaged core sample. The estimated values of oil recovery for base case, after damage process and after inhibition of asphaltene precipitation using nanofluid are 51.6%, 36.1% and 46.7%, respectively. The results showed the reduction in core damage after using nanofluid. In addition, the relative permeability curves are plotted for the base case, after damage process and also after inhibition of asphaltene precipitation using nanofluid. Comparison of relative permeability curves shows, relative permeability of oil phase decreased after damage process as compared with the base case. But after using nanofluid the oil relative permeability curve has shifted to the right and effective permeability of oil phase has been improved.

关键词： Formation damage Enhanced oil recovery Salinity Asphaltene Core flooding Nano particles

Cloud service selection using cloud service brokers: approaches and challenges

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Frontiers of Computer Science 2019年第3期13卷 599-617页

作者： Meysam VAKILI Neda JAHANGIRI Mohsen sharifi Department of Computer Engineering University of Science and Culture Tehran 14619-68151 Iran School of Computer Engineering Iran University of Science and Technology Tehran 16846-13114 Iran

Cloud computing users are faced with a wide variety of services to choose from. Consequently, a number of cloud service brokers (CSBs) have emerged to help users in their service selection process. This paper reviews the recent approaches that have been introduced and used for cloud service brokerage and discusses their challenges accordingly. We propose a set of attributes for a CSB to be considered effective. DifFerent CSBs' approaches are classified as either single service or multiple service models. The CSBs are then assessed, analyzed, and compared with respect to the proposed set of attributes. Based on our studies, CSBs with multiple service models that support more of the proposed effective CSB attributes have wider application in cloud computing environments.

关键词： cloud service broker (CSB) cloud service selection cloud computing quality of service (QoS)

New dynamic permeability upscaling method for flow simulation under depletion drive and no-crossflow conditions

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Petroleum Science 2013年第2期10卷 233-241页

作者： Mohammad sharifi Mohan Kelkar McDougall School of Petroleum Engineering The University of Tulsa800 South Tucker DriveTulsaOklahoma74104United States

The main purpose of upscaling in reservoir simulation is to capture the dynamic behavior of fine scale models at the coarse scale. Traditional static or dynamic methods use assumptions about the boundary conditions to determine the upscaled properties, in this paper, we show that the upscaled properties are strongly dependent on the flow process observed at the fine scale. We use a simple no- crossflow depletion drive process and demonstrate that an upscaled property is not a constant value. Instead, if the goal is to match the performance of the fine scale model, the upscaled permeability changes with time. We provide an analytical solution to determine the upscaled permeability and present the value of upscaled permeability under limiting conditions. Our equation suggests that it is possible that upscaled value can fall outside the range of fine scale values under certain conditions. We show that for pseudo steady state flow, using common averaging methods like arithmetic or even geometric averaging methods can lead to optimistic results. We also show that the no-crossflow solution is significantly different than crossflow solution at late times. We validate our method by comparing the results of the method with flow simulation results in two and multi-layered models.

关键词： Upscaling permeability reservoir simulation no-crossflow depletion drive

Coupled and splitting bedload sediment transport models based on a modified flux-wave approach

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International Journal of Sediment Research 2021年第1期36卷 38-49页

作者： Hossein Mahdizadeh Soroosh sharifi Department of Civil Engineering University of Birjand Department of Civil Engineering University of Birmingham

Numerical modeling of free-surface flow over a mobile bed with predominantly bedload sediment transport can be done by solving the shallow water and Exner equations using coupled and splitting *** coupled method uses a coupling of the governing equations at the same time step leading to a non-conservative *** splitting method solves the Exner and the shallow water equations in a separate manner,and is only capable of modeling weak free-surface and bedload *** the current study,an extended version of a Godunov-type wave propagation algorithm is presented for modeling of morphodynamic systems using both coupled and splitting *** the introduced coupled method the entire morphodynamic system is solved in the form of a conservation *** the splitting technique,a new wave Riemann decomposition is defined which enables the scheme to be utilized for mild and strong *** consider the bedload sediment discharge within the Exner equation,the Smart and Meyer-Peter & Miiller formulae are *** was found that the coupled solution gives accurate predictions for all investigated flow regimes including pro pagation over a dry-state using a Courant-Friedrichs-Lewy(CFL) number equal to ***,the splitting method was able to model all flow regimes with a lower CFL number of 0.3.

关键词： Bedload sediment transport Coupled solution Flux-wave method Shallow water equations Splitting technique Wave propagation algorithm

Synthesis of highly selective and stable mesoporous Ni-Ce/SAPO-34 nanocatalyst for methanol-to-olefin reaction:Role of polar aprotic N,N-dimethylformamide solvent

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Particuology 2018年第5期16卷 113-122页

作者： Hossein Akhoundzadeh Majid Taghizadeh Hassan sharifi Pajaie Chemical Engineering Department Bahai Noshirvani University of TechnologyP.O.Box 484Babo***Iran Wood and Paper Science Department Faculty of Natural ResourcesSariAgricultural Sciences and Natural Resource UniversityP.O.Box 737SariIran

A series of mesoporous nanocrystalline silicoaluminophosphate (SAPO)zeolites (SAPO-34)were synthesized via an ultrasonic and microwave-assisted hydrothermal method in the presence of [3- (trimethoxysilyl)propyl]octadecyldimethylammonium chloride and cetyltrimethylammonium bromide surfactants as soft *** and cerium were then doped on SAPO-34using incorporation and impregnation methods,and all the catalysts were applied to the methanol-to-olefin (MTO)reaction. The catalysts were characterized using X-ray diffraction,field-emission scanning electron microcopy, inductively coupled plasma-atomic emission spectroscopy,transmission electron microscopy,Fourier- transform infrared spectroscopy,Brunauer-Emmett-Teller analysis,NH3temperature-programmed desorption analysis,and thermogravimetric *** the impregnation method,the effect of using protic or aprotic solvents as impregnation media on the physico-chemical properties of the metal-based SAPO-34was *** and N,N-dimethylformamide (DMF)were employed as the protic and aprotic solvents,*** catalyst prepared using the aprotic DMF solvent exhibited higher dispersion and lower aggregation of metal species compared with that prepared using the protic water ***,the sample synthesized using the incorporation method exhibited good catalytic performance;however,the Ni-Ce[SAPO-34 sample prepared using the impregnation method and aprotic DMF solvent exhibited superior catalytic performance in the MTO reaction.

关键词： Ni-Ce/SAPO-34 MTO reaction Impregnation Aprotic solvent Protic solvent

Shape factor for regular and irregular matrix blocks in fractured porous media

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Petroleum Science 2020年第1期17卷 136-152页

作者： Peyman Rostami Mohammad sharifi Morteza Dejam Department of Petroleum Engineering Amirkabir University of Technology(Polytechnic of Tehran)Hafez AvenueP.O.Box 15875-4413TehranIran Department of Petroleum Engineering College of Engineering and Applied ScienceUniversity of Wyoming1000 E.University AvenueLaramieWY 82071-2000USA

Describing matrix–fracture interaction is one of the most important factors for modeling natural fractured reservoirs.A common approach for simulation of naturally fractured reservoirs is dual-porosity modeling where the degree of communication between the low-permeability medium(matrix)and high-permeability medium(fracture)is usually determined by a transfer *** of the proposed matrix–fracture functions depend on the geometry of the matrix and fractures that are lumped to a factor called shape ***,there is no unique solution for calculating the shape factor even for symmetric *** fine-scale modeling is a tool for calculating the shape factor and validating the current solutions in the *** this study,the shape factor is calculated based on the numerical simulation of fine-grid simulations for single-phase flow using finite element *** the best of the author’s knowledge,this is the first study to calculate the shape factors for multidimensional irregular bodies in a systematic *** models were used,and shape factors were calculated for both transient and pseudo-steady-state(PSS)cases,although in some cases they were not clarified and assumptions were not *** boundary condition dependency of the shape factor was also investigated,and the obtained results were compared with the results of other *** show that some of the most popular formulas cannot capture the exact physics of matrix–fracture *** obtained results also show that both PSS and transient approaches for describing matrix–fracture transfer lead to constant shape factors that are not unique and depend on the fracture pressure(boundary condition)and how it changes with time.

关键词： Fractured reservoirs Shape factor Matrix–fracture boundary conditions Computational fluid dynamic(CFD)

A new post-coding approach for PAPR reduction in DC-biased optical OFDM systems

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Optoelectronics Letters 2019年第4期15卷 302-305页

作者： Abbas Ali sharifi Department of Electrical Engineering University of Bonab

The high peak-to-average power ratio(PAPR) is one of the main drawbacks in orthogonal frequency division multiplexing(OFDM) communication systems, which also exists in the optical OFDM(O-OFDM) systems. In this letter, a new approach based on the discrete Hartley transform(DHT) post-coding technique is proposed to reduce PAPR of an O-OFDM signal in visible light communication systems. The proposed method is compared with Walsh-Hadamard transform(WHT) and discrete cosine transform(DCT) techniques in terms of PAPR reduction and bit error rate(BER)performance. Experimental results indicate that the proposed DHT post-coding method remarkably reduces the PAPR of an OFDM signal for optical intensity modulated direct detection systems without any corruption in the BER performance.

关键词： peak-to-average power ratio(PAPR) optical OFDM(O-OFDM) discrete Hartley transform(DHT)