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Enhanced removal of nitrate and phosphate from wastewater by Chlorella vulgaris: Multi-objective optimization and CFD simulation

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Chinese Journal of Chemical Engineering 2019年第3期27卷 639-648页

作者： mohammad Bagher Sabeti mohammad Amin Hejazi Afzal Karimi Faculty of Chemical and Petroleum Engineering University of Tabriz Department of Food Biotechnology Branch for Northwest & West Region Agricultural Biotechnology Research Institute of Iran Agricultural Education and Extension Organization (AREEO) Department of Biotechnology Faculty of Advanced Technologies in Medicine Iran University of Medical Sciences

To enhance the efficiency of wastewater biotreatment with microalgae, the effects of physical parameters need to be investigated and optimized. In this regard, the individual and interactive effects of temperature, p H and aeration rate on the performance of biological removal of nitrate and phosphate by Chlorella vulgaris were studied by response surface methodology(RSM). Furthermore, a multi-objective optimization technique was applied to the response equations to simultaneously find optimal combinations of input parameters capable of removing the highest possible amount of nitrate and phosphate. The optimal calculated values were temperature of 26.3 °C, pH of 8 and aeration rate of 4.7 L·min^(-1). Interestingly, under the optimum condition, approximately 85% of total nitrate and 77% of whole phosphate were removed after 48 h and 24 h, respectively, which were in excellent agreement with the predicted values. Finally, the effect of baffle on mixing performance and, as a result, on bioremoval efficiency was investigated in Stirred Tank Photobioreactor(STP) by means of Computational Fluid Dynamics(CFD). Flow behavior indicated substantial enhancement in mixing performance when the baffle was inserted into the tank. Obtained simulation results were validated experimentally. Under the optimum condition, due to proper mixing in baffled STP, nitrate and phosphate removal increased up to 93% and 86%,respectively, compared to unbaffled one.

关键词： Nitrate Phosphate Nutrient removal Response surface methodology Stirred Tank Photobioreactor Computational Fluid Dynamics

Evaluation of seismic reliability of gravity dam-reservoirinhomogeneous foundation coupled system

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Frontiers of Structural and Civil Engineering 2019年第3期13卷 701-715页

作者： Hamid Taghavi GANJI mohammad ALEMBAGHERI mohammad Houshmand KHANEGHAHI Department of Civil and Environmental Engineering Amirkabir University of TechnologyTehranIran Department of Civil and Environmental Engineering Tarbiat Modares UniversityTehranIran Department of Civil Engineering Shahid Beheshti UniversityTehranIran

The seismic performance of gravity dam-reservoir-foundation coupled system is investigated utilizing probabilistic *** this research,the uncertainties associated with modeling parameters are incorporated in nonlinear response history simulations to realistically quantify their effects on the seismic performance of the *** methodology is applied to Pine Flat gravity dam and the foundation is considered to be inhomogeneous assuming a constant spatial geometry but with various rock material *** sources of uncertainty are taken into account in the reliability analysis using Latin Hypercube Sampling *** effects of the deconvolution process,number of samples,and foundation inhomogeneity are investigated.

关键词： gravity dams dam-reservoir-foundation interaction seismic reliability inhomogeneous foundation earthquake deconvolution

Geometrically Nonlinear Bending Analysis of Metal-Ceramic Composite Beams under Thermomechanical Loading

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Chinese Journal of Mechanical Engineering 2013年第4期26卷 701-713页

作者： TORABIZADEH mohammad Amin Department of Industrial Design Engineering University of Applied Science and Technology

A new method is developed to derive equilibrium equations of Metal-Ceramic beams based on first order shear deformation plate theory which is named first order shear deformation beam theory2(FSDBT2). Equilibrium equations obtained from conventional method (FSDBT1) is compared with FSDBT2 and the case of cylindrical bending of Metal-Ceramic composite plates for non-linear thermomechanical deformations and various loadings and boundary conditions. These equations are solved by using three different methods (analytical, perturbation technique and finite element solution). The through-thickness variation of the volume fraction of the ceramic phase in a Metal-Ceramic beam is assumed to be given by a power-law type function. The non-linear strain-displacement relations in the von-Kármán sense are used to study the effect of geometric non-linearity. Also, four other representative averaging estimation methods, the linear rule, Mori-Tanaka, Self-Consistent and Wakashima-Tsukamoto schemes, by comparing with the power-law type function are also investigated. Temperature distribution through the thickness of the beams in thermal loadings is obtained by solving the one-dimensional heat transfer equation. Finally it is concluded that for Metal-Ceramic composites, these two theories result in identical static responses. Also the displacement field and equilibrium equations in the case of cylindrical bending of Metal-Ceramic plates are the same as those supposed in FSDBT2.

关键词： thermomechanical loading functionally graded beams monlinear analysis analytical solution

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

Optimization of a continuous ultrasound assisted oxidative desulfurization(UAOD) process of diesel using response surface methodology(RSM) considering operating cost

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Chinese Journal of Chemical Engineering 2020年第5期28卷 1384-1396页

作者： mohammad Dana mohammad Amin Sobati Shahrokh Shahhosseini Aminreza Ansari School of Chemical Engineering Iran University of Science and Technology(IUST)TehranIran

A continuous-flow ultrasound-assisted oxidative desulfurization(UAOD)of partially hydro-treated diesel has been investigated using hydrogen peroxide-formic acid as simple and easy to apply oxidation *** effects of different operating parameters of oxidation stage including residence time(2–24 min),formic acid to sulfur molar ratio(10–150),and oxidant to sulfur molar ratio(5–35)on the sulfur removal have been studied using response surface methodology(RSM)based on Box–Behnken *** the operating costs of the continuous-flow oxidation stage including chemical and electrical energy consumption,the appropriate values of operating parameters were selected as follows:residence time of 16 min,the formic acid to sulfur molar ratio of 54.47,and the oxidant to sulfur molar ratio of *** these conditions,the sulfur removal and the volume ratio of the hydrocarbon phase to the aqueous phase were 86.90%and 4.34,*** drastic reduction in the chemical consumption in the oxidation stage,the volume ratio of the hydrocarbon phase to the aqueous phase was increased up to ***,the formic acid to sulfur molar ratio and the oxidant to sulfur molar ratio were obtained 23.64 and 3.58,respectively,which lead to sulfur removal of 84.38%with considerable improvements on the operating cost of oxidation stage in comparison with the previous works.

关键词： Ultrasound-Assisted Oxidative Desulfurization(UAOD) Continuous-flow system Sulfur removal Response Surface Methodology(RSM) Operating cost

Production of ultra-transparent glass-ceramics via controlled crystallization of nanocrystals in the glassy matrix of LAST

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International Journal of Minerals,Metallurgy and Materials 2014年第1期21卷 71-76页

作者： mohammad Sadegh Shakeri Materials and Energy Research Center(MERC)

Microstructural variation in glass-ceramics encompasses the range from nanocrystalline transparent materials to microcrystalline tough materials. In this investigation, the crystallization process was controlled for the development of ultra transparent LiEO-A1203-SiO2 glass-ceramics containing TiO2 as a nucleating agent （LAST）. Results of UV-Vis absorption spectra were compared with the expected theo- retical values calculated by the Rayleigh scattering method for the determination of ultra transparency. Results of the investigation illustrate that the control of crystallization increases the range of ultra transparency by the reduction of crystal size and their uniformity in the glassy matrix. Last but not the least, the optimized samples are ultra transparent approximately in the whole light wavelengths.

关键词： glass-ceramics transparency nanocrystals crystallization

Chaos in a fractional-order micro-electro-mechanical resonator and its suppression

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Chinese Physics B 2012年第10期21卷 159-167页

作者： mohammad Pourmahmood Aghababa Electrical Engineering Department Urmia University of TechnologyUrmiaIran

The present paper investigates the existence of chaos in a non-autonomous fractional-order micro-electromechanical resonator system（FOMEMRS）.Using the maximal Lyapunov exponent criterion,we show that the FOMEMRS exhibits *** attractors of the system are plotted to validate its chaotic ***,a novel fractional finite-time controller is introduced to suppress the chaos of the FOMEMRS with model uncertainties and external disturbances in a given finite *** the latest version of the fractional Lyapunov theory,the finite time stability and robustness of the proposed scheme are ***,we present some computer simulations to illustrate the usefulness and applicability of the proposed method.

关键词： micro-electro-mechanical resonator chaotic behavior fractional calculus fractional finite-time controller

Eco-friendly green synthesis of novel magnetic Fe3O4/SiO2/ZnO-Pr6O11 nanocomposites for photocatalytic degradation of organic pollutant

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Journal of Rare Earths 2020年第1期38卷 13-20页

作者： mohammad Ali Ebrahimzadeh Sobhan Mortazavi-Derazkola mohammad Ali Zazouli Pharmaceutical Sciences Research Center Hemoglobinopathy Institute and Department of Medicinal ChemistrySchool of PharmacyMazandaran University of Medical ScienceSariP.O.Box 48471-93698Iran Department of Environmental Health Engineering Health Science Research CenterFaculty of HealthMazandaran University of Medical ScienceSariP.O.Box 48471-16548Iran

This study reports the successful so nochemical synthesis of novel Fe3O4/SiO2/ZnO-Pr6O11(Fe/Si/Zn-Pr6O11) nanocomposites using fructose as a green capping *** influence of various parameters containing capping agent,power and time of ultrasound irradiation was investigated to reach optimum morphology and size *** products obtained were characterized by transmission electron microscopy(TEM),UV/Vis diffuse reflectance spectroscopy(DRS),Fourier transform infrared spectra(FT-IR),vibration sample magnetometer(VSM),scanning electron microscopy(SEM),energy dispersive X-ray microanalysis(EDS) and X-ray diffraction(XRD).The Fe3O4/SiO2/ZnO-Pr6O11 nanocomposites display remarkably enhanced photocatalytic activity towards rhodamine b degradation(89.6%)and Congo red(84.7%) under UV irradiation compared with the other *** results illustrate that the photocatalytic efficiency of magnetic nanocomposites is very much higher than pure *** photocatalyst still has good stability after five successive ***,these recyclable nanocomposites can play a role in the treatment of both industrial and domestic contaminated water.

关键词： Sonochemical synthesis Nanocomposite Photocatalysis Electron microscopy Rhodamine b Praseodymium oxide

CeO_(2)and CeO_(2)-based nanomaterials for photocatalytic,antioxidant and antimicrobial activities

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Journal of Rare Earths 2023年第2期41卷 167-181页

作者： Shaidatul Najihah Matussin mohammad Hilni Harunsani mohammad Mansoob Khan Chemical Sciences Faculty of ScienceUniversiti Brunei DarussalamJalan Tungku LinkGadongBE 1410Brunei Darussalam

Cerium oxide(CeO_(2)),one of the most significant rare-earth oxides,has attracted considerable interest over the past *** is primarily due to the ease in Ce^(3+)/Ce^(4+)redox ability as well as other factors that affect the efficacy of CeO_(2)and CeO_(2)-based ***_(2)and CeO_(2)-based materials have shown enhanced responses in catalytic and photocatalytic activities for environmental and biological *** addition,the formation of Ce^(3+)and oxygen vacancies in CeO_(2)has aided in enhancing CeO_(2)*** order to produce oxygen-deficient CeO_(2)and CeO_(2)-based materials,a variety of synthesis methods were used and are highlighted in this ***,this review compiles and discusses the mechanisms that involve oxygen vacancies,defects,and Ce^(3+)formation for environmental applications,such as photocatalytic dye degradation,photocatalytic CO_(2)reduction,and non-colored pollutants *** biological applications of CeO_(2),such as antioxidant enzyme mimetic,antioxidant reactive oxygen species/reactive nitrogen species,and antimicrobial activities,are also ***,future prospects are also suggested for future development and detailed investigations.

关键词： Oxygen vacancies Oxygen deficient CeO_(2) Ce^(3+)/Ce4^(+) Environmental applications Biological applications Rare earths