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International Journal of Biomathematics 2017年第1期10卷 127-151页

作者： Navid Freidoonimehr mohammad mehdi rashidi mohammad Hossein Momenpour Saman rashidi Young Researchers and Elite ClubHamedan Branch Islamic Azad University Hamedan Iran Shanghai Key Lab of Vehicle Aerodynamics and Vehicle Thermal Management Systems 4800 Cao An Rd. Jiadong Shanghai 201804 P. R. China ENN-Tongji Clean Energy Institute of Advanced Studies Shanghai P. R. China Department of Mechanical Engineering Ferdowsi University of Mashhad Mashhad Iran

The paper provides an analytical investigation, homotopy analysis method （HAM）, of the heat and mass transfer for magnetohydrodynamic Oldroyd-B nanofluid flow over a stretching sheet in the presence of convective boundary condition. The PDE governing equations, which consist of equations of continuity, momentum, energy and nanoparti- cles, are converted to ordinary differential equations using similarity transformations. The current HAM solution demonstrates very good correlation with those of the pre- viously published studies in the special cases. The influences of different flow physical parameters such as the Deborah numbers in terms of relaxation and retardation times （/3i, /32）, magnetic parameter （M）, Prandtl number （Pr）, Brownian motion parameter （Nb）, thermophoresis parameter （Nt）, Lewis number （Le）, and Biot number （Bi） on he fluid velocity component （f＇（η））, temperature distribution （θ（η）） and concentration φ（η）） as well as the local Nusselt number （Nux/Rex ） and the local Sherwood number （Shx/Re1/2 ） are discussed in detail.

关键词： MHD non-Newtonian fluid nanofluid stretching sheet homotopy simu-lation.

Predictor homotopy analysis method for nanofluid flow through expanding or contracting gaps with permeable walls

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International Journal of Biomathematics 2015年第4期8卷 145-159页

作者： Navid Freidoonimehr Behnam Rostami mohammad mehdi rashidi Young Researchers and Elite Club Hamedan Branch Islamic Azad University Hamedan Iran Shanghai Key Lab of Vehicle Aerodynamics and Vehicle Thermal Management Systems4800 Cao An Rd. Jiadong Shanghai 201804 P. R. China ENN-Tongji Clean Energy Institute of Advanced Studies Shanghai P. R. China Mechanical Engineering DepartmentEngineering Faculty of Bu-Ali Sina University Hamedan Iran

In this paper a definitely new analytical technique, predictor homotopy analysis method （PHAM）, is employed to solve the problem of two-dimensional nanofluid flow through expanding or contracting gaps with permeable walls. Moreover, comparison of the PHAM results with numerical results obtained by the shooting method coupled with a Runge- Kutta integration method as well as previously published study results demonstrates high accuracy for this technique. The fluid in the channel is water containing different nanoparticles： silver, copper, copper oxide, titanium oxide, and aluminum oxide. The effects of the nanoparticle volume fraction, Reynolds number, wall expansion ratio, and different types of nanoparticles on the flow are discussed.

关键词： Nanofluid permeable walls porous channel non-dimensional wall dilationrate predictor homotopy analysis method.

Special Column on Recent Advances in PCMs as Thermal Energy Storage in Energy Systems

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Journal of Thermal Science 2024年第2期33卷 395-395页

作者： mohammad Hossein AHMADI Tingzhen MING Marc A.ROSEN S.A.SHERIF mohammad mehdi rashidi Shahrood University of Technology Iran Wuhan University of Technology China University of Ontario Institute of Technology Canada University of Florida USA University of Electronic Science and Technology of China China

Thermal energy storage technology has the advantages of high energy storage density,small size,and high energy conversion *** is one of the key energy storage technologies and an important way to achieve carbon peaking and carbon neutrality *** change materials (PCMs) offer this opportunity to store high amount of energy and release it in the form of latent heat when needed,and therefore have the advantage of being capable to alleviate the intrinsic intermittency of renewable power production,especially in wind and solar farms.

关键词： efficiency store latent

Modified Differential Transform Method (DTM) Simulation of Hydromagnetic Multi-Physical Flow Phenomena from a Rotating Disk

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World Journal of Mechanics 2011年第5期1卷 217-230页

作者： mohammad mehdi rashidi Esmael Erfani Osman Anwar Bég Swapan Kumar Ghosh 不详

A similarity solution for the steady hydromagnetic convective heat and mass transfer with slip flow from a spinning disk with viscous dissipation and Ohmic heating yields a system of non-linear, coupled, ordinary differential equations. These equations are analytically solved by applying a newly developed method namely the DTM-Padé technique which is a combination of the Differential Transform Method (DTM) and the Padé approximation. A full analytical solution is presented, as a benchmark for alternative numerical solutions. DTM-Padé is implemented without requiring linearization, discretization, or perturbation, and holds significant potential for solving strongly nonlinear differential equations which arise frequently in fluid dynamics. The regime studied is shown to be controlled by the slip parameter (γ), magnetohydrodynamic body force parameter (M), Eckert (viscous heating) number (Ec), Schmidt number (Sc), Soret number (Sr), Dufour number (Du) and Prandtl number (Pr). The influence of selected parameters on the evolution of dimensionless velocity, temperature and concentration distributions is studied graphically. Increasing magnetic field (M) is found to significantly inhibit the radial (f) and tangential (g) velocities, but to accentuate the axial velocity field (h);furthermore temperature (θ) and concentration (φ) are both enhanced with increasing M. Increasing Soret number (Sr) acts to boost the dimensionless concentration (φ). Temperatures are significantly elevated in the boundary layer regime with a rise in Eckert number (Ec). Excellent correlation between the DTM-Padé technique and numerical (shooting) solutions is achieved. The model has important applications in industrial energy systems, process mechanical engineering, electromagnetic materials processing and electro-conductive chemical transport processes.

关键词： Differential Transform Method Padé Approximants Thermal-Diffusion Heat Transfer Soret Effect Boundary-Layers Hydromagnetics Slip Dissipation Electromagnetic Processing of Materials

Inverted organic solar cells with solvothermal synthesized vanadium-doped TiO2 thin films as efficient electron transport layer

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Chinese Physics B 2017年第9期26卷 406-410页

作者： mehdi Ahmadi Sajjad rashidi Dafeh Samaneh Ghazanfarpour mohammad Khanzadeh Department of Physics Faculty of ScienceVali-e-Asr University of RafsanjanRafsanjanIran

We investigated the effects of using different thicknesses of pure and vanadium-doped thin films of TiO2 as the electron transport layer in the inverted configuration of organic photovoltaic cells based on poly（3-hexylthiophene） P3HT：[6-6] phenyl-（6） butyric acid methyl ester（PCBM）. 1% vanadium-doped TiO2nanoparticles were synthesized via the solvothermal method. Crystalline structure, morphology, and optical properties of pure and vanadium-doped TiO2 thin films were studied by different techniques such as x-ray diffraction, scanning electron microscopy, transmittance electron microscopy, and UV–visible transmission spectrum. The doctor blade method which is compatible with roll-2-roll printing was used for deposition of pure and vanadium-doped TiO2 thin films with thicknesses of 30 nm and 60 nm. The final results revealed that the best thickness of TiO2 thin films for our fabricated cells was 30 nm. The cell with vanadium-doped TiO2 thin film showed slightly higher power conversion efficiency and great Jsc of 10.7 mA/cm^2 compared with its pure counterpart. In the cells using 60 nm pure and vanadium-doped TiO2 layers, the cell using the doped layer showed much higher efficiency. It is remarkable that the external quantum efficiency of vanadium-doped TiO2 thin film was better in all wavelengths.

关键词： inverted polymer solar cells electron transport layer vanadium-doped TiO2 thin films solvothermal

A Galvanostatic Modeling for Preparation of Electrodeposited Nanocrystalline Coatings by Control of Current Density

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Journal of Materials Science & Technology 2012年第12期28卷 1071-1076页

作者： Ali mohammad rashidi School of Engineering Razi UniversityP.O. Box 67149-67346 Kermanshah Iran

The correlation between the grain size of electrodeposited coatings and the current densities was modeled by considering galvanostatic conditions. In order to test the model by experimental results, nanocrystalline （NC） nickel samples were deposited at different current densities using a Watts bath. The grain size of the deposits was evaluated by X-ray diffraction （XRD） technique. Model predictions were validated by finding a curve being the best-fit to the experimental results which were gathered from literature for different NC coatings in addition to those data measured in this research for NC nickel coatings. According to our model, the variation of grain size with the reciprocal of the current density follows a power law. A good agreement between the experimental results and model predictions was observed which indicated that the derived analytical model is applicable for producting the nanocrystalline electrodeposits with the desired grain size by controling current density.

关键词： Electrodeposition Galvanostatic modeling Grain size control Nanocrystalline

A new robust predictive model for lost circulation rate using convolutional neural network:A case study from Marun Oilfield

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Petroleum 2023年第3期9卷 468-485页

作者： Farshad Jafarizadeh Babak Larki Bamdad Kazemi mohammad Mehrad Sina rashidi Jalil Ghavidel Neycharan mehdi Gandomgoun mohammad Hossein Gandomgoun Department of Petroleum Engineering Amirkabir University of TechnologyTehranIran Department of Petroleum Engineering Omidiyeh Branch of Islamic Azad UniversityOmidiyehIran Science and Research Branch Islamic Azad UniversityTehranIran Faculty of Mining Petroleum and Geophysics EngineeringShahrood University of TechnologyShahroodIran Department of Information Technology and Computer Engineering Shahid Madani University of AzerbaijanTabrizIran Faculty of Petroleum Engineering Sahand University of TechnologyTabrizIran

A major cause of some of serious issues encountered in a drilling project,including wellbore instability,formation damage,and drilling string stuck e which are known to increase non-productive time(NPT)and hence the drilling cost e is what we know as mud *** mud loss can be prevented or at least significantly reduced by taking proper measures beforehand provided the position and intensity of such loss can be properly predicted using an accurate predictor ***,in this study,we used the convolutional neural network(CNN)and hybridized forms of multilayer extreme learning machine(MELM)and least square support vector machine(LSSVM)with the Cuckoo optimization algorithm(COA),particle swarm optimization(PSO),and genetic algorithm(GA)for modeling the mud loss rate based on drilling data,mud properties,and geological information of 305 drilling wells penetrating the Marun *** this purpose,we began by a pre-processing step to attenuate the effect of noise using the Savitzky-Golay *** whole set of available data was divided into the modeling(including 2300 data points)and the validation(including 483 data points)***,the second generation of the non-dominated sorting genetic algorithm(NSGA-Ⅱ)was applied to the modeling data to identify the most significant features for estimating the mud *** results showed that the prediction accuracy increased with the number of selected features,but the increase became negligible when the number of selected features exceeded ***,the following 9 features were selected as input to the intelligent algorithms(IAs):pump pressure,mud weight,fracture pressure,pore pressure,depth,gel 10 min/gel 10 s,fan 600/fan 300,flowrate,and formation *** of the hybrid algorithms and simple forms of LSSVM and CNN to the training data(80%of the modeling data,i.e.1840 data points)showed that all of the models tend to underestimate the mud loss at higher mud loss rates,although the CNN exhibited l

关键词： Lost circulation prediction Artificial intelligence Deep learning Feature selection

Evaluation of behaviors of earth and rockfill dams during construction and initial impounding using instrumentation data and numerical modeling

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第4期9卷 709-725页

作者： mohammad rashidi S. Mohsen Haeri University of Texas at El Paso El Paso USA Sharif University of Technology Tehran Iran

In this study,the behavior of Gavoshan dam was evaluated during construction and the first impounding.A two-dimensional（2D） numerical analysis was conducted based on a finite difference method on the largest cross-section of the dam using the results of instrument measurements and back *** evaluations will be completed in the case that back analysis is carried out in order to control the degree of the accuracy and the level of confidence of the measured behavior since each of the measurements could be controlled by comparing it to the result obtained from the numerical *** that,by comparing the results of the numerical analysis with the measured values,it is indicated that there is a proper consistency between these two ***,it was observed that the dam performance was suitable regarding the induced pore water pressure,the pore water pressure ratio r;,settlement,induced stresses,arching degree,and hydraulic fracturing probability during the construction and initial impounding *** results demonstrated that the maximum settlement of the core was 238 cm at the end of *** the following 6 years after construction（initial impounding and exploitation period）,the accumulative settlement of the dam was 270 *** is clear that 88% of the total settlement of the dam took place during dam *** reason is that the clay core was smashed in the wet side,*** optimum moisture *** the average curving ratio was 0.64 during dam construction; at the end of the initial impounding,the maximum amount of curving ratio in the upstream was 0.81,and the minimum（critical） amount in the downstream was *** was also concluded that this dam is safe in comparison with the behaviors of other similar dams in the world.

关键词： Earth and rockfill dams Initial impounding Numerical modeling Instrumentation Settlement Pore pressure

Prediction of immiscible gas flooding performance:a modified capacitance-resistance model and sensitivity analysis

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Petroleum Science 2019年第5期16卷 1086-1104页

作者： Seyed Hamidreza Yousefi Fariborz rashidi mohammad Sharifi mohammad Soroush Department of Petroleum Engineering Amirkabir University of TechnologyTehranIran Department of Chemical Engineering Amirkabir University of TechnologyTehranIran Petroleum Engineering Department University of Trinidad and TobagoCouvaTrinidad and Tobago

Reservoir performance prediction is one of the main steps during a field development *** to the complexity and time-consuming aspects of numerical simulators,it is helpful to develop analytical tools for a rapid primary *** capacitance-resistance model(CRM)is a simple technique for reservoir management and *** method is an advanced time-dependent material balance equation which is combined with a productivity *** uses production/injection data and bottom-hole pressure as inputs to build a reliable model,which is then combined with the oil-cut model and converted to a predictive *** has been studied thoroughly for water flooding *** this study,a modified model for gas flooding systems based on gas density and average reservoir pressure is developed.A detailed procedure is described in a synthetic reservoir model using a genetic ***,a streamline simulation is implemented for validation of the *** results show that the proposed model is able to calculate interwell connectivity parameters and oil production ***,a sensitivity analysis is carried out to investigate effects of drawdown pressure and gas PVT properties on the new ***,acceptable ranges of input data and limitations of the model are comprehensively discussed.

关键词： Reservoir management Capacitance-resistance model Gas flooding Analytical model Sensitivity analysis Streamline simulation

Cobalt supported on CNTs-covered γ-and nano-structured alumina catalysts utilized for wax selective Fischer-Tropsch synthesis

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Journal of Natural Gas Chemistry 2012年第6期21卷 713-721页

作者： mohammad Reza Hemmati mohammad Kazemeini Farhad Khorasheh Jamshid Zarkesh Alimorad rashidi Sharif University of Technology(SUT) Department of Chemical & Petroleum Engineering Research Institute of Petroleum Industry(RIPI)

Cobalt supported on carbon nanotubes （CNTs）-covered alumina has been recently developed and successfully utilized as a catalyst in Fischer-Tropsch synthesis （FTS）. Problems associated with shaping of Co/CNTs into extrudates or pellets as well as catalyst attrition rendered these materials unfavorable for industrial applications. In this investigation regular γ- and nano-structured （N-S） alumina as well as CNTs-covered regular γ- and N-S-alumina supports were impregnated by cobalt nitrate solution to make new cobalt-based catalysts which were also promoted by Ru. The catalysts were characterized and tested in a micro reactor to evaluate their applicability in FTS. γ-Al2O3 was prepared by calcination of bohemite and N-S-Al2O3 was prepared by sol-gel method using aluminum chloride as starting material. Catalyst evaluations indicated that N-S-Al2O3 was superior to regular γ-Al2O3 and that CNTs-covered alumina supports were favored over non-covered ones in terms of activity and heavy hydrocarbon selectivity. These were justified by porosimetric characteristics of the catalysts and existence of CNTs points of view. CNTs-covered catalysts also showed higher wax selectivity and better resistance to deactivation. Furthermore, TPR analysis indicated that the cobalt aluminate phase, which is responsible for the permanent deactivation of alumina supported Co-based catalysts, did not form on alumina supported Co-based catalysts covered with CNTs due to weaker interactions between cobalt and alumina.

关键词： Fischer-Tropsch synthesis nano-structured alumina gamma alumina carbon nanotubes catalyst deactivation