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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

Finite Element Analysis of the Influence of Artificial Cementation on the Strength Parameters and Bearing Capacity of Sandy Soil under a Strip Footing

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Open Journal of Civil Engineering 2023年第2期13卷 221-236页

作者： mohammad T. Alkhamis Abdulla AL-rashidi Department of Civil Engineering Public Authority for Applied Education and Training Shuwaikh Kuwait

Artificial cementation is a method commonly used to enhance and improve soil properties. This paper investigates the effect of using different amounts of cement on soil strength parameters and soil bearing capacity, using the finite element method. Experimental tests are conducted on soil samples with different amounts of Portland cement. A 2-D numerical model is created and validated using the numerical modelling software, COMSOL Multiphysics 5.6 software. The study finds that the cohesion, and the angle of the internal friction of the soil samples increase significantly as a result of adding 1%, 2%, and 4% of Portland cement. The results demonstrate that the stresses and strain under the strip footing proposed decrease by 3.24% and 7.42%. Moreover, the maximum displacement also decreases by 1.47% and 2.97%, as a result of adding cements of 2% and 4%. The bearing capacity values obtained are therefore excellent, especially when using the 2% and 4% cement. The increase identified is due to the increased values of the bearing capacity factors. It is concluded that from an economic viewpoint, using 2% cement is the best option.

关键词： Artificial Cementation Strength Parameters Bearing Capacity Finite Element Method Strip Footing

Improving methane storage on wet activated carbons at various amounts of water

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燃料化学学报 2012年第4期40卷 385-389页

作者： mohammad JABER DARABI MAHBOUB ALI AHMADPOUR HAMED rashidi Department of Chemical Engineering Faculty of EngineeringFerdowsi University of Mashhad

Different mesoporous activated carbons were prepared by both chemical and physical activation processes and were examined for methane uptake in the presence of *** isotherms were obtained at wet condition by wetting samples with water at mass ratio of water/carbon(R) close to *** compare,the amount of methane storage were also measured at dry *** maximum amount of methane stored was attained as 237 V/V at R=1.0 by hydrate formation at the methane critical *** the next step,mass ratios of water/carbon were changed to investigate various amount of water for methane storage *** other values of mass ratio of water/carbon(R=0.8 and 1.4) were selected and methane isotherms were obtained at the same *** values of 210 and 248 V/V were reached for methane storage,*** was also observed that,in the pressure range lower than hydrate pressure,by increasing water ratio the hydrate formation pressure was decreased and methane uptake was much less than that of dry condition due to pore filling by water.

关键词： methane storage hydrate isotherm water wetting

Synthesis of vinasse-dolomite nanocomposite biochar via a novel developed functionalization method to recover phosphate as a potential fertilizer substitute

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Frontiers of Environmental Science & Engineering 2020年第4期14卷 173-188页

作者： Nima Kamali Abdollah rashidi Mehrabadi Maryam Mirabi mohammad Ali Zahed Civil Water and Environmental Engineering FacultyShahid Beheshti University A.C.TehranIran Cell and Molecular Biology Department Faculty of Biological SciencesKharazmi UniversityTehranIran

The effectiveness of phosphate(P)removal from aqueous solutions was investigated by novel low-cost biochars synthesized from vinasse and functionalized with calcined *** vinasse-derived biochar,synthesized via pyrolysis at different temperatures,showed easy preparation and a large surface *** novel vinasse biochar nanocomposites were prepared by adding dolomite to the vinasse biochars with different weight percentages(10,20 and 30%).The characteristics of the prepared materials were identified for further understanding of the inherent adsorption mechanism between P ions and vinasse ***-dolomite nanocomposite was very effective in the adsorption of P species from aqueous *** effect of the operational factors on Vinasse-dolomite nanocomposite was explored by applying response surface methodology(RSM).According to RSM results,the optimum condition was achieved to be contact time 90(min),250(mg/L)of P concentration and pH *** isotherm and kinetic studies were applied on experimental data to understand the adsorption *** Vinasse-dolomite nanocomposite revealed preferential P species adsorption in the presence of co-existing *** P species could be recovered by 1.0 MHC 1 where the efficiency was not affected up to the fifth *** P-loaded Vinasse-dolomite nanocomposite was successfully tested on a plant;it significantly improved its growth and proved its potency as a P-based fertilizer substitute.

关键词： Biochar Vinasse Dolomite Phosphate Fertilizer

Genetic algorithm application for matching ordinary black oil PVT data

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Petroleum Science 2012年第2期9卷 199-211页

作者： mohammad Taghizadeh Sarvestani Behnam Sedaee Sola Fariborz rashidi Department of Petroleum Engineering Amirkabir University of Technology Tehran Iran Institute of Petroleum Engineering University of Tehran Tehran Iran Department of Chemical Engineering Amirkabir University of Technology Tehran Iran

In the study of reservoirs, it is vital that we have a realistic physical model of the reservoir fluid that accurately describes the hydrocarbon system and its properties. The available equations of state （EOS） to model the fluid phase behavior have some inherent deficiencies that may cause erroneous predictions for real reservoir fluids, so these models should be tuned against experimental data by adjusting some parameters. Since there are many matching parameters, tuning the EOS against experimental data is a tedious and difficult work. In this study, a genetic algorithm as an optimization technique is used to solve this regression problem. This study presents a new method that uses a specially designed genetic algorithm to search for suitable regression parameters to match the EOS against measured data. The proposed method has been tested on three real black oil samples. The results show the surprising performance of the developed genetic algorithm to match the experimental data of the selected fluid samples. The main advantage of the used method is its high speed in finding a solution. Also, finding more than one solution, working automatically, confining the role of experts to the last stage, reducing costs and having the possibility of evaluating the different situations are the other advantages of this method to match ordinary black oil PVT data and makes it an ideal method to implement as an automatic EOS tuning algorithm for black oils.

关键词： Equations of state (EOS) tuning genetic algorithms black oil chromosome regression

Spectrofluorimetric Determination of Cu^2＋ Using New Fluorogenic Reagent

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Chinese Journal of Chemistry 2005年第2期23卷 160-165页

作者： mohammad-HUSSEIN,Sorouraddin mohammad-REZA,rashidi BEHROOZ,Shabani EBRAHIM,Ghorbani-Kalhor AnalyticalChemistryDepartment FacultyofChemistryTabrizUniversityP.O.Box51664TabrizIran DrugAppliedResearchCenter TabrizUniversityofMedicalScienceTabrizIran InorganicChemistryDepartment FacultyofChemistryTabrizUniversityTabrizIran

A new synthesized fluorogenic reagent, 8-[(2-pyridine)methylideneamino] quinoline (PMAQ), was utilized for spectrofluorimetric determination of Cu(II) at trace levels. PMAQ, a good fluorogenic reagent, though insoluble in water, but is soluble in ethanol and 20% ethanol-water. The excitation and the fluorescence wavelengths of PMAQ were 310 and 434 nm respectively. When the reagent was complexed with Cu(II), the fluorescence intensity decreased proportionally with the concentration of Cu(II) at pH 4.5 by a static quenching effect. The highest sensitivity to Cu2+ determination was shown to be at PMAQ concentration of 1.0 X 10(-5) mol.L-1. In order to enhance the quenching effect, the Cu(II)-PMAQ complex solution was kept at 22 degreesC for 20 min. Though the interferences by Co(II) and Fe(III) were very serious, they were however, completely eliminated by being masked with oxalate and ascorbate ions respectively. The linear dynamic range for Cu(II) determination was between 25-441 mug.L-1 with the detection limit of 18 mug.L-1 (RSD=3.7%, n=6). The proposed method was successfully applied to the determination of Cu(II) in real samples including human blood serum, commercial tea and wheat flour.

关键词： copper determination fluorogenic reagent spectrofluorimetry

Enduring effect of permeability texture for enhancing accuracy and reducing uncertainty of reservoir fluid flow through porous media

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Petroleum Science 2020年第1期17卷 118-135页

作者： Arash Azamifard Fariborz rashidi mohammadreza Pourfard mohammad Ahmadi Bahram Dabir Department of Petroleum Engineering Amirkabir University of Technology424 Hafez AveTehranIran Department of Chemical Engineering Amirkabir University of Technology424 Hafez AveTehranIran Department of Electrical Engineering Amirkabir University of Technology424 Hafez AveTehranIran

Modeling reservoir permeability is one of the crucial tasks in reservoir simulation ***,it is done by kriging-based *** rigorous modeling of the permeability results in more reliable outputs of the reservoir ***,a new category of geostatistical methods has been used for this purpose,namely multiple point statistics(MPS).By this new category of permeability modeling methods,one is able to predict the heterogeneity of the reservoir permeability as a continuous *** methods consider the direction of property variation in addition to the distances of known locations of the *** this study,the reservoir performance of a modified version of the SPE 10 solution project as a pioneer case is used for investigating the efficiency of these methods and paralleling them with the kriging-based *** this way,the permeability texture concept is introduced by applying some MPS *** study is accomplished in the conditions of real reservoir dimensions and velocities for the whole reservoir life.A continuous training image is used as the input of calculation for the permeability *** results show that the detailed permeability of the reservoir as a continuous variable makes the reservoir simulation show the same fluid front movement and flooding behavior of the reservoir similar to the reference case with the same permeability *** MPS methods enable the reservoir simulation to reproduce the fluid flow complexities such as bypassing and oil trapping during water flooding similar to the reference ***,total oil production is predicted with higher accuracy and lower *** studied cases are identical except for the permeability *** histograms and variograms of permeabilities for the studied reservoir are quite similar,but the performance of the reservoir shows that kriging-based method results have slightly less accuracy than some MPS ***,it results in lower

关键词： Multiple point statistics Permeability modeling Fluid flow in porous media Permeability texture