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Fabrication and densification enhancement of SiC-particulate-reinforced copper matrix composites prepared via the sinter-forging process

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International Journal of Minerals,Metallurgy and Materials 2014年第9期21卷 934-939页

作者： mohammadmehdi Shabani mohammad Hossein Paydar mohammad Mohsen Moshksar Department of Materials Science and Engineering School of Engineering Shiraz University

The fabrication of copper （Cu） and copper matrix silicon carbide （Cu/SiCp） particulate composites via the sinter-forging process was investigated. Sintering and sinter-forging processes were performed under an inert Ar atmosphere. The influence of sinter-forging time, temperature, and compressive stress on the relative density and hardness of the prepared samples was systematically investigated and subsequently compared with that of the samples prepared by the conventional sintering process. The relative density and hardness of the composites were enhanced when they were prepared by the sinter-forging process. The relative density values of all Cu/SiCp composite samples were observed to decrease with the increase in SiC content.

关键词： metallic matrix composites particle reinforced composites silicon carbide forging sintering bulk density

Nickel doped zinc oxide nanoparticles produced by hydrothermal decomposition of nickel-doped zinc hydroxide nitrate

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Particuology 2012年第4期10卷 492-496页

作者： mohammad Yeganeh Ghotbi Nanomaterials and Nanotechnology Program Ceramic Engineering DepartmentFaculty of EngineeringMalayer UniversityMalayerIran

Zinc hydroxide nitrate, an anionic exchanger layered material, undoped as well as doped with 2-10% nickel, was synthesized by using a pH-controlled precipitation method. The layered materials were then used to produce the undoped and nickel-doped zinc oxides by hydrothermal-treatment. X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy confirmed the formation of pure phase undoped and nickel-doped layered materials, as well as the products of the hydrothermal- treated materials, nanostructured zinc oxides. Optical studies of the nanostructured zinc oxides showed a decrease in band gap with increasing content of the doping agent, nicke~.

关键词： NanostructureNickel doped zinc oxideChemical synthesisBand gap

Fabrication,microstructure,and optical properties of nanocrystalline transparent LAST glass ceramics containing CeO_2

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International Journal of Minerals,Metallurgy and Materials 2014年第4期21卷 401-407页

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

In the present research, the effect of CeO2 dopant on the fabrication of transparent lithium aluminosilicate titanate （LAST） glass ceramics was investigated. Nanocrystallineβ-quartz solid solution （s.s.） was observed to be the main phase crystallized in this system. Com-parable refractive indices of the glassy matrix andβ-quartz s.s., as well as the incorporation of very fine grains size were determined as the main reasons for retaining the transparency of the glass ceramics. CeO2 was introduced as a suitable optical agent, playing a role as a network modifier in the glass ceramics, because it does not accelerate the growth process and retards the extended growth of crystals. Optical investi-gations indicate that the Fermi energy level, direct and indirect band gaps, and Urbach energy decrease with increasing nanocrystal content in the glassy matrix of specimens, which can be related to the expansion of conduction band, the enhancement of ionic bonds in the crystal lat-tice, and the enhancement of structural arrangement degree, respectively.

关键词： glass ceramics nanocrystals alurninosilicates titanates transparency optical properties

Optimal Equilibrium Selection of Price-maker Agents in Performance-based Regulation Market

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Journal of Modern Power Systems and Clean Energy 2022年第1期10卷 204-212页

作者： mohammad Rayati Aras Sheikhi Ali mohammad Ranjbar Wei Sun Department of Electrical Engineering Sharif University of TechnologyTehranIran Sharif Energy Research Institute(SERI) Sharif University of TechnologyTehranIran Department of Electrical Engineering and Computer Science University of Central FloridaOrlandoFL 32816USA

This paper analyzes the oligopolistic equilibria of multiple price-maker agents in performance-based regulation(PBR)*** these markets,there are price-maker agents representing some frequency regulation(FR)providers and a number of independent price-taker FR providers.A model of equilibrium problem with equilibrium constraints(EPECs)is employed in this paper to study the equilibria of a PBR market in the presence of price-maker agents and price-taker FR *** to the incorporation of the FR providers’dynamics,the proposed model is reformulated as a mixed-integer linear programming(MILP)problem over innovative mathematical *** optimal equilibrium point is also selected for the market,where none of the agents is the unique deviator and the dynamic performance of power system is improved *** effectiveness of the proposed optimal equilibrium point is evaluated by comparing the outputs with the conventional optimal dispatches of the FR providers.

关键词： Performance-based regulation(PBR)market multi-agent system equilibrium problem with equilibrium constraint(EPEC) frequency regulation(FR) mixed-integer linear programming(MILP)

Auto-tuning PVT data using multi-objective optimization:Application of NSGA-II algorithm

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Petroleum 2024年第1期10卷 135-149页

作者： Abdolhadi Zarifi mohammad Madani mohammad Jafarzadegan Reservoir Engineering Systems Petroleum Engineering DepartmentMain Office Building of National Iranian South Oil Company(NISOC)AhvazIran Reservoir Engineering Division Petroleum Engineering DepartmentPetroleum Engineering and Development Company(PEDEC)TehranIran Combined Planning Management National Iranian Oil Company(NIOC)TehranIran

Reservoir simulation is known as perhaps the most widely used,accurate,and reliable method for field development in the petroleum *** integral part of a reliable reservoir simulation process is to consider robust and rigorous tuned EOS ***,EOS models are tuned iteratively through arduous workflows against experimental PVT ***,this comes with a number of drawbacks such as forcingly using weight factors,which upon alteration adversely affects the optimization *** objective of the current work is thus to introduce an auto-tune PVT matching tool using NSGA-II multi-objective *** order to illustrate the robustness of the presented technique,three different PVT samples are used,including two black-oil and one gas condensate *** utilize PengRobinson EOS during all the manual and auto-tuning *** of auto-tuned EOS-generated results with those of experimental and computed statistical error values for these samples clearly show that the proposed method is *** addition,the proposed method,contrary to the manual matching process,provides the engineer with several matched solutions,which allows them to select a match based on the engineering background to be best amenable to the problem at *** addition,the proposed technique is fast,and can output several solutions within less time compared to the traditional manual matching method.

关键词： Auto-tuning PVT Equation of state NSGA-II Multi-objective optimization

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

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

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