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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

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

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

Solvent extraction of rubidium from gold waste using conventional SX and new CFE methods

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Rare Metals 2015年第11期34卷 818-828页

作者： mohammad Reza Tavakoli mohammadi Seyed mohammad javad Koleini Sepideh Javanshir Hossein Abolghasemi Mahmoud Abdollahy Mineral Processing Department Tarbiat Modares University Mining Engineering Department University of Birjand Oil and Gas Center of Excellence School of Chemical Engineering College of Engineering University of Tehran

Solvent extraction（SX） of rubidium（Rb） from leaching filtrate of gold waste（GW） in Mouteh Processing Plant by 18-crown-6（18C6） was studied. High potential of new column flotoextraction（CFE） method in extraction of Rb from dilute solutions was also demonstrated. First, the factors affecting SX of Rb from a synthetic rubidium sulfate solution(containing 100 mg·L-1Rb) were identified.0.05 mol·L-118C6 in kerosene, 0.02 mol·L-1picric acid in aqueous phase, aqueous to organic（A/O） ratio of 1, p H7 and mixing time of 15 min are the optimum values for affective factors. The three-stage precipitation with sodium carbonate, p H adjustment with sulfuric acid and two-stage evaporation and crystallization were conducted to purify the leaching from impurities such as Fe, Al, Mn, Ca and especially competing cations of K and Na. Almost complete extraction of Rb and K from final filtrate containing 0.08 mol·L-1picric acid was performed using 0.2 mol·L-118C6 in kerosene. The Rb and K strippings of 99.12 % and 9.93 %, respectively, are obtained with 2 mol·L-1nitric acid with A/O ratio of 2. Finally, the performance comparison of the CFE and SX methods in similar conditionsshows increased extraction of K and Rb by 16 % and 5 %,respectively, using CFE method.

关键词： Rubidium Gold waste Solvent extraction Column flot

Commentary regarding “on-orbit sleep problems of astronauts and countermeasures”

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Military Medical Research 2019年第2期6卷 178-182页

作者： Joseph John Bevelacqua Seyed mohammad javad Mortazavi Bevelacqua Resources 343Adair DriveRichland WA99352USA Department of Electrical Engineering Biophotonics LabUniversityof Wisconsin Milwaukee3200N Cramer StMilwaukee WI53211USA Doss Lab(R-432) Fox Chase Cancer Center333Cottman AvenuePhiladelphia PA19111USA

This commentary addresses the article by Wu et al. entitled 'On-orbit sleep problems of astronauts and countermeasures'. In this article, the authors discussed the sleep problems of astronauts. Despite its challenging topic, the paper authored by Wu et al. has at least one major shortcoming. This issue is related to the observation that the sleep pattern of astronauts can be disturbed by light flash phenomenon. Since the first report by astronaut E.E. Aldrin in 1969, many astronauts have reported light flashes. These visually perceived flashes of light occurred in different shapes but they apparently moved across the visual field of astronauts and possibly caused, at least to some extent, sleep problems. Moreover, the countermeasures proposed by the authors may improve astronauts’ sleep pattern, but they do not address the root cause of the light flashes(i.e., heavy ion interactions outside the shielding provided by the Earth’s magnetosphere). A possible approach to reducing light flashes is available using the fact that much of the galactic cosmic radiation(GCR) spectrum is composed of ions that can be diverted from the spacecraft using electromagnetic fields. Possible design parameters and the requisite electric and magnetic field strengths to successfully deflect GCR radiation are outlined.

关键词： Space radiation Astronauts Sleep problems Light flashes Phosphenes

On the accuracy of higher order displacement discontinuity method(HODDM) in the solution of linear elastic fracture mechanics problems

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Journal of Central South University 2016年第11期23卷 2941-2950页

作者： Abolfazl Abdollahipour mohammad Fatehi Marji Alireza Yarahmadi Bafghi javad Gholamnejad Faculty of Mining and Metallurgical Engineering Yazd University

The higher order displacement discontinuity method(HODDM) utilizing special crack tip elements has been used in the solution of linear elastic fracture mechanics(LEFM) problems. The paper has selected several example problems from the fracture mechanics literature(with available analytical solutions) including center slant crack in an infinite and finite body, single and double edge cracks, cracks emanating from a circular hole. The numerical values of Mode Ⅰ and Mode Ⅱ SIFs for these problems using HODDM are in excellent agreement with analytical results(reaching up to 0.001% deviation from their analytical results). The HODDM is also compared with the XFEM and a modified XFEM results. The results show that the HODDM needs a considerably lower computational effort(with less than 400 nodes) than the XFEM and the modified XFEM(which needs more than 10000 nodes) to reach a much higher accuracy. The proposed HODDM offers higher accuracy and lower computation effort for a wide range of problems in LEFM.

关键词： accuracy higher order displacement discontinuity method LEFM mode Ⅰ stress intensity factor mode Ⅱ stress intensity factor