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Performance analysis of a tuned point absorber using SPH calm water and wave tank simulations

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Journal of Ocean Engineering and Science 2024年第5期9卷 409-436页

作者： Kaveh Soleimani mohammad javad Ketabdari Department of Maritime Engineering Amirkabir University of TechnologyTehranIran

In this paper,two smoothed particle hydrodynamics(SPH)models,namely SPH-W and SPH-C were used to evaluate the motion response of a point absorber wave energy converter(WEC).In the SPH-W model,a long wave flume was constructed and a long simulation was performed to obtain the motion response of the *** the SPH-C model,the SPH method is only used to find the hydrodynamic coefficients of the device by analysing a few seconds of free-decaying motion of WEC in calm water in a much smaller numerical ***,these coefficients were inserted in the equation of motion of a heaving WEC that was solved using a 4th order Runge-Kutta(ODE45)solver in ***,the energy conservation property of the WCSPH model was examined through a standing wave benchmark ***,the wavepoint absorber interaction was *** the simulation time for SPH-C model is much smaller than that of SPH-W,it gave almost similar results for the motion response of *** two models were used to evaluate the effects of the control force and the draft of a cone-cylinder point absorber on its hydrodynamic *** results showed that compared to the effect of the supplementary inertia,changes in the draft of the WEC have a small influence on its hydrodynamic *** buoy draft has an inverse relationship with both added mass and damping ***,increasing the supplementary mass increases the added mass and decreases the hydrodynamic damping coefficients.

关键词： Point absorber Power take-off Control forces SPH wave tank test SPH calm water test DualSPHysics

A population-feedback control based algorithm for well trajectory optimization using proxy model

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第2期9卷 281-290页

作者： javad Kasravi mohammad Amin Safarzadeh Abdonabi Hashemi National Iranian Drilling Company AhwazIran Tehran Energy Consultants (TEC) Company TehranIran Department of Petroleum Engineering Petroleum University of TechnologyAhwazIran

Wellbore instability is one of the concerns in the field of drilling *** phenomenon is affected by several factors such as azimuth,inclination angle,in-situ stress,mud weight,and rock strength *** these factors,azimuth,inclination angle,and mud weight are *** objective of this paper is to introduce a new procedure based on elastoplastic theory in wellbore stability solution to determine the optimum well trajectory and global minimum mud pressure required(GMMPR).Genetic algorithm(GA) was applied as a main optimization engine that employs proportional feedback controller to obtain the minimum mud pressure required(MMPR).The feedback function repeatedly calculated and updated the error between the simulated and set point of normalized yielded zone area(NYZA).To reduce computation expenses,an artificial neural network(ANN) was used as a proxy(surrogate model) to approximate the behavior of the actual wellbore *** methodology was applied to a directional well in southwestern Iranian *** results demonstrated that the error between the predicted GMMPR and practical safe mud pressure was 4%for elastoplastic method,and 22%for conventional elastic solution.

关键词： Elastoplastic theory Normalized yielded zone area(NYZA) Optimization Well trajectory Proportional feedback controller Proxy model

Zinc oxide nanoparticles:A highly efficient and readily recyclable catalyst for the synthesis of xanthenes

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Chinese Chemical Letters 2012年第11期23卷 1225-1229页

作者： javad Safaei-Ghomi mohammad Ali Ghasemzadeh Department of Organic Chemistry Faculty of ChemistryUniversity of Kashan

A novel and efficient route for the synthesis of 1,8-dioxooctahydroxanthenes and 14-aryl-14H-dibenzo[a,j]xanthenes is described through one-pot multi-component reaction of dimedone and 2-naphthol with various aryl aldehydes using ZnO nanoparticles under solvent-free conditions. This method provides a novel and improved pathway for the synthesis of xanthenes in the terms of excellent yields, short reaction times, reusability and low catalyst loading.

关键词： ZnO nanoparticles Xanthene Solvent-free Multi-component reaction Heterogeneous catalysts

Magnesium/Nano-hydroxyapatite Composite for Bone Reconstruction: The Effect of Processing Method

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Journal of Bionic Engineering 2020年第1期17卷 92-99页

作者： mohammad Khodaei Farahnaz Nejatidanesh mohammad javad Shirani Srinivasan Iyengar Hossein Sina Omid Savabi Department of Materials Science and Engineering Golpayegan University of TechnologyGolpayegan ***Iran Dental Materials Research Center Dental Research InstituteSchool of DentistryIsfahan University of Medical SciencesIsfahan ***Iran Post graduate student of Prosthodontics Student Research CommitteeSchool of DentistryIsfahan University of Medical SciencesIsfahan ***Iran Materials Engineering Division Faculty of EngineeringLund UniversityLund 11822100Sweden European Spallation Source ERIC Lund 17622100Sweden Dental Research Center Dental Research InstituteSchool of DentistryIsfahan University of Medical SciencesIsfahan ***Iran

Nano-ceramic particles can serve as reinforcing agents for metallic materials to improve their mechanical ***,it is important to ensure chemical compatibility between the matrix and *** the present study,magnesium composites with and without nano-hydroxyapatite(nHA)particles were fabricated for bone reconstruction *** different techniques were used,Conventional Sintering(CS)of powder compacts and Spark Plasma Sintering(SPS)of pre-compacted *** showed that a 10 wt%addition of nHA particles to magnesium,followed by SPS improved the compression strength by 27%.CS did not lead to any significant improvement compared to SPS processing.X-ray diffraction data after CS revealed the formation of unfavorable phases due to chemical reactions between nHA particles and the magnesium matrix,while these phases were absent after SPS *** mechanical properties of the specimens fabricated by CS were much inferior to those processed using *** shorter processing time associated with SPS leaded to reduced interaction between nHA particles and the Mg-matrix,compared to CS.

关键词： magnesium nano-hydroxyapatite composite materials in situ reaction biomedical-materials

Numerical study of aerosol particle deposition in simple and converging-diverging micro-channels with a slip boundary condition at the wall

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Particuology 2014年第2期12卷 100-105页

作者： Seyed mohammad javad Hosseini Ataallah Soltani Goharrizi Bahador Abolpour Department of Chemical Engineering Faculty of EngineeringShahid Bahonar University of Kerman

The design of micro-devices involving aerosol transport requires the study of the deposition of aerosols in micro-channels. In this study, the slip and no-slip boundary conditions for the gas flow regime were applied to the Navier-Stokes equations to obtain the particle deposition in simple and converging-diverging micro-channels. The equation of particle motion included inertial, viscous, Brownian, and gravity terms. It was found that the ratio of gravity to inertial effects controls the deposition of particles with diameters of 0.1-1 μm, and the ratio of diffusion to inertial effects controls the deposition of particles with diameters of 0.01-0.001 i^m. Comparison between the no-slip and slip flow regimes showed that the deposition of 0.1- to 1-μm-diameter particles was less and the deposition of 0.01- to 0.001-1μm-diameter particles was greater for the slip flow regime. There was no significant difference between slip and no-slip flow regimes for the deposition of 0.01- to 0.1-μm-diameter particles. Finally, it was shown that the stagnated gas in the corners of the converging-diverging micro-channel produced similar gas velocity profiles under the slip and no-slip flow regimes.

关键词： Aerosol depositionMicro-channelConverging-diverging micro-channelSlip boundary condition

Molecular design and applications of a nanostructure green Tripodal surface active ionic liquid in enhanced oil recovery: Interfacial tension reduction, wettability alteration, and emulsification

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Petroleum Science 2023年第6期20卷 3530-3539页

作者： Mona Kharazi javad Saien Morteza Torabi mohammad Ali Zolfigol Faculty of Chemistry and Petroleum Science Bu–Ali Sina UniversityHamedan***Iran

Surface active ionic liquids (SAILs) are considered as prominent materials in enhanced oil recovery thanks to their high interfacial activity. This study reports the preparation and applications of a nanostructure Tripodal imidazolium SAIL as an environmentally-friendly substitute to the conventional surfactants. The product has a star-like molecular structure centered by a triazine spacer, namely [(C_(4)im)_(3)TA][Cl_(3)], prepared by a one-step synthesis method and characterized with FT-IR, NMR, XRD, and SEM analysis methods. The interfacial tension of the system was decreased to about 78% at critical micelle concentration of less than 0.08 mol·dm^(−3). Increasing temperature, from 298.2 to 323.2 K, improved this capability. The solid surface wettability was changed from oil-wet to water-wet and 80% and 77% stable emulsions of crude oil–aqueous solutions were created after one day and one week, respectively. Compared to the Gemini kind homologous SAILs, the superior effects of the Tripodal SAIL were revealed and attributed to the strong hydrophobic branches in the molecule. The Frumkin adsorption isotherm precisely reproduced the generated IFT data, and accordingly, the adsorption and thermodynamic parameters were determined.

关键词： Tripodal ionic liquids Green materials Enhanced oil recovery Interfacial tension Wettability Emulsification

A simple granulation technique for preparing high-porosity nano copper oxide(Ⅱ) catalyst beads

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Particuology 2011年第5期9卷 480-485页

作者： Seyed javad Ahmadi mohammad Outokesh Morteza Hosseinpour Tahereh Mousavand Jaber Ebne Hayyan Research Laboratory School of Energy Engineering Sharif University of Technology Department of Mechanical Engineering McGill University

A simple and efficient method was developed for fabricating spherical granules of CuO catalyst via a three-step procedure. In the first step, copper oxide nanoparticles were synthesized by hydrothermal decomposition of copper nitrate solution under supercritical condition. Then, they were immobilized in the polymeric matrix of calcium alginate, and followed by high-temperature calcination in an air stream as the third step, in which carbonaceous materials were oxidized, to result in a pebble-type catalyst of high porosity. The produced CuO nanoparticles were characterized by transmission electron microscopy （TEM） that revealed an average size of 5 nm, X-ray diffractometry （XRD）, and thermo gravimetric （TG） analysis. The catalysts were further investigated by BET test for measurement of their surface area, and by temperature-programmed reduction analysis （H2-TPR） for determination of catalytic activity. The results demonstrated that immobilization of the CuO nanoparticle in the polymeric matrix of calcium alginate, followed by calcination at elevated temperatures, could result in notable mechanical strength and enhanced catalytic activity due to preservation of the high surface area, both valuable for practical applications.

关键词： CuO nanoparticles Catalyst Hydrothermal synthesis Supercritical water Granulation Calcium alginate

Aminopropyl-containing ionic liquid based organosilica as a novel and efficient adsorbent for removal of crystal violet from wastewaters

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Chinese Journal of Chemical Engineering 2017年第9期25卷 1294-1302页

作者： Frood Shojaeipoor Bakhshali Masoumi mohammad Hossain Banakar javad Rastegar Department of Chemistry Payame Noor University Department of Chemistry Yasouj University

Herein a novel aminopropyl-containing ionic liquid based organosilica(ILOS-NH_2) is prepared, characterized and applied as effective adsorbent for removal of crystal violet(CV) dye from wastewater. The ILOS-NH2 material was synthesized by hydrolysis and co-condensation of 1,3-bis-(3-trimethoxysilylpropyl)-imidazolium chloride(BTMSPIC) under acidic conditions followed by treatment with 3-aminopropyl-trimethoxysilane in toluene under reflux conditions. This material was characterized using scanning electron microscopy(SEM), diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS), thermal gravimetric analysis(TGA) and energy dispersive X-ray analysis(EDAX). The material was effectively used in the removal of crystal violet at ambient temperature and showed high capacity and stability under applied conditions. The efficacy of p H, contact time, adsorbent dose, initial dye concentration, temperature, and isotherm studies and the applicability of pseudo-first, second order and Elovich kinetic models have also been investigated.

关键词： Ionic liquid based organosilica Aminopropyl-functionalized Crystal violet(CV) Isotherm Kinetic

Procedure for determining the number of thermal diffusion columns in square cascade for separation of Ne stable isotopes

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Nuclear Science and Techniques 2023年第5期34卷 47-55页

作者： Fatemeh Mansourzadeh mohammad Mahdi Shadman javad Karimi Sabet Valiyollah Ghazanfari Nuclear Fuel Cycle Research School Nuclear Science and Technology Research InstituteTehranIran

The thermal diffusion column represents one method of separating stable *** method is advantageous for smallscale operations because of the simplicity of the apparatus and small inventory,especially in gas-phase ***,it has attracted attention for its applicability in tritium and noble gas separation *** this study,the R cascade was used to design and determine the number of columns.A square cascade was adopted for the final design because of its flexibility,and calculations were performed to separate 20Ne and 22Ne *** the R cascades that enriched the Ne isotopes by more than 99%were investigated,the number of columns was determined,and the square cascade parameters were optimized using the specified ***,a calculation code“RSQ_CASCADE”was developed.A unit separation factor of three was considered,and the number of studied stages ranged from 10 to *** results showed that the column separation power,relative total flow rate,and required number of columns were linearly related to the number of *** separation power and relative total flow decreased and the number of columns increased as the stage number ***,a cascade of 85 columns is recommended to separate the stable Ne *** calculations yielded a 17-stage square cascade with five columns in each *** changing the stage cut,feed point,and cascade feed flow rate,the best parameters for the square cascade were determined according to the cascade and column separation *** the column separation power had a maximum value in cascade feed 50,it was selected for separating Ne isotopes.

关键词： Stable isotope Thermal diffusion Cascade Separation Neon