检索结果-南通市图书馆

Ethylene absorption in N-methyl-2-pyrrolidone/silver nano-solvent:Thermodynamics and kinetics study

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2021年第8期34卷 57-66页

作者： mohammad Yousefi Shima azizi S.m.Peyghambarzadeh Zoha azizi Department of Chemical Engineering Mahshahr BranchIslamic Azad UniversityMahshahrIran

The effect of presence of silver nanoparticles in pure N-methyl-2-pyrrolidone(NmP)solvent for ethylene gas absorption in an experimental pressure decaying setup has been *** experiments were performed at temperatures of 278.15 K,298.15 K and 328.15 K and different pressures(up to ethylene dew point)as well as different concentrations of silver nanoparticles(0.05 g·L^(-1) and 0.1 g·L^(-1)).The kinetic data of absorption,Henry’s law constants,and heat of absorption were *** of the pure solvent and the nanofluids absorption results revealed that the presence of small amounts of nanoparticles could improve the absorption performance between 1.5%-18%.Finally,the effect of temperature,pressure,and nanoparticle concentration on the equilibrium results were investigated.

关键词： Absorption Ethylene N-methyl-2-pyrrolidone(NmP) Nanoparticles Solubility

Progressive failure analysis of notched composite plate by utilizing macro mechanics approach

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2021年第3期15卷 623-642页

作者： Seyed m.N.GHOREISHI mahdi FAKOOR Ahmad azizi Faculty of New Sciences and Technologies University of TehranTehran***Iran Department of mechanical Engineering Science and Research BranchIslamic Azad UniversityTehran***Iran

In this study,gradual and sudden reduction methods were combined to simulate a progressive failure in notched composite plates using a macro mechanics *** the presented method,a progressive failure is simulated based on a linear softening law prior to a catastrophic failure,and thereafter,sudden reduction methods are employed for modeling a progressive *** combination method significantly reduces the computational cost and is also capable of simultaneously predicting the first and last ply failures(LPFs)in composite *** proposed method is intended to predict the first ply failure(FPF),LPF,and dominant failure modes of carbon/epoxy and glass/epoxy notched composite *** addition,the effects of mechanical properties and different stacking sequences on the propagation of damage in notched composite plates were *** results of the presented method were compared with experimental data previously reported in the *** comparing the numerical and experimental data,it is revealed that the proposed method can accurately simulate the failure propagation in notched composite plates at a low computational cost.

关键词： progressive failure notched composite plate Hashin failure criterion macro mechanics approach finite element method

Size-dependent modal interactions of a piezoelectrically laminated microarch resonator with 3:1 internal resonance

在线全文

学校读者我要写书评

暂无评论

Applied mathematics and mechanics(English Edition) 2020年第10期41卷 1517-1538页

作者： A.NIKPOURIAN m.R.GHAZAVI S.azizi mechanical Engineering Department Tarbiat Modares UniversityTehran 14115-111Iran mechanical Engineering Department Urmia University of TechnologyUrmia 57166-93187Iran

The nonlinear interactions of a microarch resonator with 3:1 internal resonance are *** microarch is subjected to a combination of direct current(DC)and alternating current(AC)electric *** piezoelectric layers are thoroughly bonded on the top and bottom surfaces of the *** piezoelectric actuation is not only used to modulate the stiffness and resonance frequency of the resonator but also to provide the suitable linear frequency ratio for the activation of the internal *** size effect is incorporated by using the so-called modified strain gradient *** system is highly nonlinear due to the co-existence of the initial curvature,the mid-plane stretching resulting from clamped anchors,and the electrostatic *** eigenvalue problem is solved to conduct a frequency analysis and identify the possible regions for activating the internal *** effects of the piezoelectric actuation,the electric excitation,and the small-scale effect are investigated on the internal *** nonlinear phenomena such as Hopf bifurcation and hysteresis are identified in the microarch *** is shown that by applying appropriate piezoelectric actuation,one is able to activate microarch internal resonance regardless of the initial rise level of the *** is also disclosed that among all the parameters,AC electric voltage has the greatest effect on the energy exchange between the interacting *** results can be used to design resonators and internal resonance based micro-electro-mechanical system(mEmS)energy harvesters.

关键词： microarch resonator internal resonance multiple time scales method micro-electro-mechanical system(mEmS) piezoelectric actuation electrostatic excitation

CFD modeling of a spouted bed with a porous draft tube

在线全文

学校读者我要写书评

暂无评论

Particuology 2010年第5期8卷 415-424页

作者： Salar azizi Seyyed Hossein Hosseini m.moraveji Goodarz Ahmadi Chemical Engineering Department Faculty of EngineeringArak University Department of Chemical Engineering Faculty of EngineeringIlam University Department of mechanical and Aeronautical Engineering Clarkson University

Spouted bed with a porous draft tube is used for drying of grains and chemical products and thermal disinfestations process. This work provides a computational fluid dynamics （CFD） simulation of binary mixtures of glass particles in a spouted bed with a porous draft tube. The simulation used the multi-fluid Eulerian-Eulerian approach based on kinetic theory of granular flows, incorporating a kinetic-frictional constitutive model for dense assemblies of particulate solids and Gidaspow＇s drag model for the interaction between gas and particles. Influences of solids mass fraction and inlet gas flow rate on pressure distribution, gas and particle velocities were studied. The modeling results were compared with the exper- imental work of Ishikura, Nagashima, and Ide （2003） for the flow condition along the axis of the spouted bed. Good agreement between the modeling results and experimental data was observed.

关键词： Spouted bedPorous dra tubeHydrodynamicsKinetictheoryCFD

Effect of TiO2 loading on the morphology and CO2/CH4 separation performance of PEBAX-based membranes

在线全文

学校读者我要写书评

暂无评论

Frontiers of Chemical Science and Engineering 2019年第3期13卷 517-530页

作者： Navid azizi mojgan Isanejad Toraj mohammadi Reza m. Behbahani Research and Technology Center of membrane Processes Chemical Engineering DepartmentIran University o f Science and Technology (IUST)NarmakTehranIran Gas Engineering Department Petroleum University of TechnologyAhwazIran

membranes have attracted much attention as economical methods for industrial chemical processes. The effects of the titanium dioxide nanoparticle load on the morphology and CO2/CH4 separation performance of poly (ether-block-amide)(PEBAX-1657) mixed matrix membranes (mmms) were investigated from pressures of 3-12 bar and temperatures of 30℃-60℃. The PEBAX membranes were characterized by scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermal gravimetric analysis, atomic force microscopy and tensile strength analysis. The incorporation of TiO2 nanoparticles into the polymeric mmms improved the CO2/CH4 gas separation performance (both the permeability and selectivity) of the membranes. The CO2 permeability and ideal CO2/CH4 selectivity values of the nanocomposite membrane loaded with 8 wt-% TiO2 were 172.32 Barrer and 24.79, respectively whereas those of the neat membrane were 129.87 Barrer and 21.39, respectively.

关键词： mixed matrix membrane TiO2 nanoparticles PEBAX-1657 C02/CH4 separation

An efficient correlation for calculating compressibility factor of natural gases

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Natural Gas Chemistry 2010年第6期19卷 642-645页

作者： Navid azizi Dr.R.Behbahani Dr.m.A.Isazadeh Gas Engineering Department Petroleum University of Technology

Compressibility factor （z-factor） values of natural gases are necessary in most petroleum engineering *** arises when there are few available experimental data for the required composition,pressure and temperature *** of the most common methods of calculating z-factor values is empirical ***,a new correlation based on the famous Standing-Katz （S-K） Chart is presented to predict z-factor *** advantage of this correlation is that it is explicit in z and thus does not require an iterative solution as is required by other ***,the comparison between new one and other correlations is carried out and the results indicate the superiority of the new correlation over the other correlations used to calculate z-factor.

关键词： natural gas compressibility factor explicit correlation

SImULATION OF VISCOELASTIC FLUID FLOWS IN EXPANSION GEOmETRY USING FINITE VOLUmE APPROACH

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2013年第12期31卷 1599-1612页

作者： morteza azizi Ahmad Ramazani S.A Habib Etemadi m Ehsan Shirzaei S Department of Chemical and Petroleum Engineering Sharif University of Technology

The simulation results on viscoelastic fluid flows in sudden expansion geometry with different expansion ratios are presented. Oldroyd-B, linear Phan-Thien-Tanner （L-PTT） and Finitely Extensible Nonlinear Elastic （FENE-P） based constitutive equations were applied in two-dimensional Cartesian coordinates. The governing equations in transient and fully developed regions were solved using open source software called OpenFOAm. The flow patterns, including velocity profiles, shear stresses and first normal stress differences in some horizontal and vertical sections are illustrated. In addition, effects of the fluid type, flow dynamics and expansion ratio on the flow and vortex patterns in transient and fully developed regions are presented and discussed. The presented results show that existences of vortices cause the inverse velocity and negative stresses in expansion regions of the channel which increase with increment of expansion ratio and Weissenberg number （We）. Furthermore, some dead spaces can be observed at channel expansion regions close to the wall which are also increased. The results also show that at low We numbers all fluids show close behavior while at high We numbers the FENE-P fluid behavior shows high divergence from that of the two other fluids.

关键词： Expansion flow Simulation Finite Volume OpenFOAm Viscoelastic Fluids.

Numerical evaluation of turbulence models for dense to dilute gas-solid flows in vertical conveyor

在线全文

学校读者我要写书评

暂无评论

Particuology 2012年第5期10卷 553-561页

作者： Salar azizi Dariush mowla Goodarz Ahmadi Chemical Engineering Department School of Chemical and Petroleum EngineeringShiraz UniversityShiraz 71345-1789Iran Department of mechanical and Aeronautical Engineering Clarkson UniversityPotsdamNY 13699-5725USA

A two-fluid model （TFm） ofmultiphase flows based on the kinetic theory and small frictional limit boundary condition of granular flow was used to study the behavior of dense to dilute gas-solid flows in vertical pneumatic conveyor. An axisymmetric 2-dimensional, vertical pipe with 5.6 m length and 0.01 m internal diameter was chosen as the computation domain, same to that used for experimentation in the literature. The chosen particles are spherical, of diameter 1.91 mm and density 2500 kg/m3. Turbulence interaction between the gas and particle phases was investigated by Simonin＇s and Ahmadi＇s models and their numerical results were validated for dilute to dense conveying of particles. Flow regimes transition and pressure drop were predicted. Voidage and velocity profiles of each phase were calculated in radial direction at different lengths of the conveying pipe. It was found that the voidage has a minimum, and gas and solid velocities have maximum values along the center line of the conveying pipe and pressure drop has a minimum value in transition from dense slugging to dilute stable flow regime. Slug length and pressure fluctuation reduction were predicted with increasing gas velocity, too. It is shown that solid phase tur- bulence plays a significant role in numerical prediction of hydrodynamics of conveyor and the capability of particles turbulence models deDends on tuning parameters of sliD-wall boundarv condition.

关键词： Vertical gas-solid flowTFmKinetic theoryTurbulenceNumerical modeling

Determining effective criteria for the selection of mDF industry locations in mazandaran Province: Application of AHP

在线全文

学校读者我要写书评

暂无评论

Forestry Studies in China 2013年第3期15卷 222-230页

作者： m.azizi m.RAmEZANZADEH Faculty of Natural Resources University of Tehran

Selecting the optimum location with attention to conditions and restrictions is one of the most importantfactors in establishing a manufacturing plant. Identification of effective criteria is an important stage in the selection for the location of industrial units. In this study, an analytic hierarchy process （AHP） was applied to select the most effective criteria for the location of mDF （medium density fiberboard） industry in mazandaran Province, Iran. A consideration in ttaining this goal is that mazandaran is favored over other provinces because of its resources of raw lignocellulosic ma- erial required for wood and paper industries. The results indicate that the criterion of ＂materials and products＂ and the ub-criterion of ＂reliability of supply of raw material＂ are the most important factors.

关键词： criterion AHP mDF industry selection of location mazandaran Province