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Effect of Gaussian size distribution width on minimum fluidization velocity in tapered gas–solid fluidized beds

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Particuology 2022年第7期20卷 71-84页

作者： Mojtaba Rasteh Goodarz Ahmadi s.h.hosseini Department of Chemical Engineering Hamedan University of TechnologyHamedanP.O.Box 65155-579Iran Department of Mechanical and Aeronautical Engineering Clarkson UniversityPotsdamNY 13699-5725USA Department of Chemical Engineering Ilam UniversityIlam 69315-516Iran

This paper investigated the effect of Gaussian distribution width,average particle diameter,particle loading,and the tapered angle on minimum fluidization velocity(U_(mf))by conducting extensive experiments in tapered fluidized *** powders with Gaussian size distribution and different distribution widths were used in the *** increase in U_(mf)with increasing the average particle diameter,particle loading,and the tapered angle was *** was also a nonmonotonic behavior of Umf as the Gaussian distribution width *** empirical correlation including dimensionless groups for predicting Umf in tapered beds was developed in which the effect of distribution width was *** proposed correlation predictions were in good agreement with the experimental data,with a maximum deviation of 16.5%and average and standard deviations of,respectively,6.4%and 7.4%.The proposed correlation was also compared with three earlier models,and their accuracy was discussed.

关键词： Tapered fluidized bed Minimum fluidization velocity Gaussian size distribution Distribution width Dimensional analysis

Effect of samarium oxide on structural,optical and electrical properties of some alumino-borate glasses with constant copper chloride

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Journal of Rare Earths 2020年第7期38卷 770-775,I0004页

作者： M.s.sadeq h.Y.Morshidy Basic sciences Dept. Faculty of EngineeringSinai Univ.45511Al-ArishEgypt

The glass system under study was prepared and examined using the melt quenching procedures and XRD to emphasize the amorphous nature,*** of the prepared solid glass system was performed by a spectrophotometer in wavelengths from 190 to 1099 *** traditional techniques and standard formulas,the density,molar volume,refractive index,optical band gap and the optical filter characteristics were determined,then the influence of samarium oxide on some properties like the structure and optical,also the electrical properties were dissected.A novel formula was proposed to estimate the refractive index from the optical energy *** obtained samples are good optical filters especially the sample that contains 0.8 mol% of sm2 *** this sample has the utmost density,the least molar volume,the maximum transmittance,least refractive index,the highest optical band gap and the least dc conductivity.

关键词： Alumino borate glasses samarium oxide Optical properties Rare earths

The anisotropic grain size effect on the mechanical response of polycrystals:The role of columnar grain morphology in additively manufactured metals

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Journal of Materials science & Technology 2024年第14期181卷 240-256页

作者： s.Amir h.Motaman Dilay Kibaroglu Institut für Eisenhüttenkunde RWTH Aachen UniversityIntzestraße 1Aachen 52072Germany

Additively manufactured(AM)metals exhibit highly complex microstructures,particularly in terms of grain morphology which typically features heterogeneous grain size distribution,irregular and anisotropic grain shapes,and the so-called columnar *** conventional morphological descriptors based on grain shape idealization are generally inadequate for representing complex and anisotropic grain mor-phology of AM *** primary aspect of microstructural grain morphology is the state of grain boundary spacing or grain size whose effect on the mechanical response is known to be *** this paper,we formally introduce the notion of axial grain size from which we derive mean axial grain size,effective grain size,and grain size anisotropy as robust morphological descriptors ca-pable of effectively representing highly complex grain *** instantiated a discrete sample of polycrystalline aggregate as a representative volume element(RVE)featuring random crystallographic orientation and misorientation ***,the instantiated RVE incorporates the typical mor-phological features of AM microstructures including distinctive grain size heterogeneity and anisotropic grain size owing to its pronounced columnar grain *** ensured that any anisotropy ob-served in the macroscopic mechanical response of the instantiated sample primarily originates from its underlying anisotropic grain *** RVE was then employed for mesoscale full-field crystal plasticity simulations corresponding to uniaxial tensile deformation along various axes via a spectral solver and a physics-based crystal plasticity constitutive model which was developed,calibrated,and validated in ear-lier *** the numerical analyses,we isolated the contribution of anisotropic grain size to the anisotropy in the mechanical response of polycrystalline aggregates,particularly those with the charac-teristic complex grain morphology of AM *** contribution c

关键词： Axial grain size Grain size anisotropy strain hardening anisotropy Grain morphology Morphological texture Columnar grains Additive manufacturing

Oscillatory flow of second grade fluid in cylindrical tube

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Applied Mathematics and Mechanics(English Edition) 2013年第9期34卷 1097-1106页

作者： A.ALI s.AsGhAR h.h.ALsULAMI Laboratoire Jean Alexandre Dieudonne Universite de Nice Sophia Antipolis Department of Mathematics Commission on Science and Technology for Sustainable Development in the SouthInstitute of Information Technology Department of Mathematics King Abdulaziz University

The unsteady oscillatory flow of an incompressible second grade fluid in a cylindrical tube with large wall suction is studied analytically. Flow in the tube is due to uniform suction at the permeable walls, and the oscillations in the velocity field are due to small amplitude time harmonic pressure waves. The physical quantities of interest are the velocity field, the amplitude of oscillation, and the penetration depth of the oscillatory wave. The analytical solution of the governing boundary value problem is obtained, and the effects of second grade fluid parameters are analyzed and discussed.

关键词： second grade fluid cylindrical coordinate oscillatory flow incompressible flow laminar flow Navier-stokes equation partial differential equation Wentzel- Kramers-Brillouin (WKB) approximation

Approximate solution of D-Dimensional Klein-Gordon Equation with hulthn-Type Potential via sUsYQM

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Communications in Theoretical Physics 2011年第9期56卷 423-428页

作者： h.hassanabadi s.Zarrinkamar h.Rahimov Physics Department Shahrood University of TechnologyShahroodIran P.O.Box ***-316 ShahroodIran Department of Basic sciences Garmsar BranchIslamic Azad University Computer Engineering Department Shahrood University of Technology

Approximate analytical solutions of the D-dimensional Klein-Gordon equation are obtained for the scalarand vector general hulthen-type potential and position-dependent mass with any l by using the concept of supersymm... 详细信息

关键词： Klein-Gordon equation D-dimensional space supersymmetric quantum mechanics

Novel typology of accelerated carbonation curing:using dry and pre-soaked biochar to tune carbon capture and mechanical properties of cementitious mortar

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Biochar 2023年第1期5卷 621-640页

作者： h.W.Kua s.M.h.Tan Department of the Built Environment College of Design and EngineeringNational University of SingaporeSingaporeSingapore

One of the challenges of promoting accelerated carbonation curing(ACC)of concrete as a carbon sequestration strategy is ensuring that carbonation will not deteriorate mechanical *** study examined the mechanical strength,water sorptivity and carbonation efficiency of ten types of mortar containing dry or pre-soaked biochar subjected to internal and/or external *** results obtained enabled a typology of ACC to be proposed,in which the carbon dioxide absorption of mortar containing various types of CO_(2)-dosed biochar ranged between 0.022%and 0.068%per unit dosage *** particular,the mortar containing dry biochar dosed with carbon dioxide was the top candidate for concurrently increasing both compressive strength(54.9 MPa)and carbon dioxide absorption(0.055%per unit dosage hour).Mortar containing pre-soaked biochar dosed with carbon dioxide was identified as a strategy that achieved the highest carbonation efficiency(0.068%per unit dosage hour),but it also reduced compressive strength(45.1 MPa).Collectively,the proposed typology offers a useful overview of the different ways by which biochar can be used to tune ACC in mortar,according to any technical constraints and/or intended functions of the carbonated concrete components.

关键词： Biochar Pre-soaked Carbonation effectiveness Carbonation efficiency Accelerated carbonation curing

Frequency equations of nonlocal elastic micro/nanobeams with the consideration of the surface effects

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Applied Mathematics and Mechanics(English Edition) 2018年第8期39卷 1089-1102页

作者： h.s.ZhAO Y.ZhANG s.T.LIE school of Civil and Environmental Engineering Nanyang Technological University

A nonlocal elastic micro/nanobeam is theoretically modeled with the consideration of the surface elasticity, the residual surface stress, and the rotatory inertia,in which the nonlocal and surface effects are considered. Three types of boundary conditions, i.e., hinged-hinged, clamped-clamped, and clamped-hinged ends, are examined. For a hinged-hinged beam, an exact and explicit natural frequency equation is derived based on the established mathematical model. The Fredholm integral equation is adopted to deduce the approximate fundamental frequency equations for the clamped-clamped and clamped-hinged beams. In sum, the explicit frequency equations for the micro/nanobeam under three types of boundary conditions are proposed to reveal the dependence of the natural frequency on the effects of the nonlocal elasticity, the surface elasticity, the residual surface stress, and the rotatory inertia, providing a more convenient means in comparison with numerical computations.

关键词： Fredholm integral equation micro/nanobeam natural frequency nonlocal elasticity surface effect

Analytic solutions in the acoustic black hole analogue of the conical Kerr metric

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Chinese Physics C 2017年第4期41卷 33-37页

作者： h. s. Vieira Departamento de Ffsica Universidade Federal da Paraiba Caixa Postal 5008 CEP 58051-970 Joao Pessoa PB Brazil Centro de Ciencias Tecnologia e Saude Universidade Estadual da Parafba CEP 58233-000 Araruna PB Brazil

We study the sound perturbation of a rotating acoustic black hole in the presence of a disclination. The radial part of the massless Klein-Gordon equation is written into a heun form, and its analytical solution is obtained. These solutions have an explicit dependence on the parameter of the disclination. We obtain the exact hawking-Unruh radiation spectrum.

关键词： draining bathtub fluid flow disclination topological defect massless Klein-Gordon equation confluent heun function black hole radiation

Geometric Phase of a Coupled system

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Communications in Theoretical Physics 2004年第5X期42卷 672-674页

作者： h.s.Abdel-Aziz MathematicsDepartment FacultyofScienceSouthValleyUniversitySohagEgypt

In this contribution, my main attention is paid to the study of the geometric phase ora two-level *** expansion of the eigenvalue and analytic information are obtained. The results are illustrated with an application ... 详细信息

关键词：几何相位二平面偏微分方程量子论