Hossein Hosseinzadeh

• Iran University of Science and Technology

In this paper stability of numerical solution of Fredholm integral equation of the first kind is studied for radial basis kernels which possess positive Fourier transform. As a result, the equivalence relation between strong and weak forms of partial differential equations (PDEs) is proved for some special radial test functions. Also the stability...

In this paper boundary elements method (BEM) is equipped with finite difference approximation (FDA) to solve two-dimensional Navier–Stokes (N–S) equation. The N–S equation is converted to a system of ordinary differential equations (ODEs) respect to time in streamfunction-vorticity formulation. The constant direct BEM and 9-point stencil FDA are ut...

The article is devoted to extension of boundary element method (BEM) for solving coupled equations in velocity and induced magnetic field for time dependent magnetohydrodynamic (MHD) flows through a rectangular pipe. The BEM is equipped with finite difference approach to solve MHD problem at high Hartmann numbers up to 106. In fact, the finite diff...

The uniqueness of solution of boundary integral equations (BIEs) is studied here when geometry of boundary and unknown functions is assumed piecewise constant. In fact we will show the BIEs with 3–times monotone radial kernels have unique piecewise constant solution. In this paper non–negative radial function is introduced which has important contr...

Boundary elements method (BEM) 2D Laplace equation Discretization error Circular arc elements (CAE) Error analysis a b s t r a c t The boundary element method (BEM) is a popular technique to solve engineering problems. We compare the circular arc elements (CAE) discretization to both linear and quadratic discretizations. The main aim of this paper...

a b s t r a c t The solution of Poisson's equation is essential for many branches of science and engineer-ing such as fluid-mechanics, geosciences, and electrostatics. Solution of two-dimensional Poisson's equations is carried out by BEM based on Galerkin Vector Method in which the integrals that appear in the boundary element method are expressed...

Keywords: 2D boundary elements method (BEM) Magneto-hydrodynamic equation (MHD) High Hartmann numbers a b s t r a c t In this article the constant and the continuous linear boundary elements methods (BEMs) are given to obtain the numerical solution of the coupled equations in velocity and induced magnetic field for the steady magneto-hydrodynamic (...

Keywords: Boundary elements method (BEM) Multiple reciprocity method (MRM) Dual reciprocity method (DRM) 2D potential problems Singular and near singular integrals The complex space C a b s t r a c t The solution of Poissons equation is essential in many branches of science and engineering such as fluid-mechanics, geosciences, and electrostatics. S...

Superabsorbent hydrogels based on poly(vinyl alcohol) were prepared by a crosslinking technique using glutaraldehyde as a crosslinker. The hydrogel structure was confirmed using scanning electron microscopy (SEM). Results from SEM observation showed a porous structure with smooth surface morphology of the hydrogel. We have systematically optimized...

A novel smart superabsorbent hydrogel with salt- and pH-responsiveness properties was obtained by grafting of mixtures of acrylic acid (AA) and acryl amide (AM) monomers onto pectin, using ammonium persulfate (APS) as a free radical initiator in the presence of methylene bisacrylamide (MBA) as a crosslinker. The graft copolymerization conditions we...

Poly(vinyl alcohol) hydrogels have a significant range of mechanical properties based on compositional and processing parameters. Biodegradable hydrogels based on Poly(vinyl alcohol) were prepared for controlled drug delivery of bovine serum albumin. These hydrogels were synthesized by a crosslinking technique using glutaraldehyde as a crosslinker....

The present work focused on the design of drug delivery system (DDS) based on a pH-sensitive amphiphilic hydrogel with interpenetrating polymer networks (IPN) structure. The IPN was constructed with hydrophilic poly(acrylic acid) (PAA) and hydrophobic poly(styrene) (PST) by a free radical polymerization technique. It is found that the presence of h...

The present study is aimed at developing novel type of interpenetrating polymeric network (IPN) hydrogels of chitosan with poly(acrylic acid) for the controlled release of amphetamine drug. IPN hydrogels were synthesized by simultaneous polymerization/crosslinking of acrylic acid monomer in the presence of chitosan and crosslinker. The swelling pro...

The boundary element method (BEM) is a popular method of solving linear partial differential equations, and it can be applied in many areas of engineering and science including fluid mechanics, acoustics, electromagnetics. The circular arc element (CAE) method is a scheme to discretize the boundary of problems arising in the BEM. In Dehghan and Hos...

In this paper, a novel biopolymer-based superabsorbent hydrogel composite based on carboxymethylcellulose (CMC) has been prepared via graft copolymerization of acrylic acid in the presence of kaolin powder using methylenebisacrylamide as a crosslinking agent and ammonium persulfate as an initiator. The synthetic variables i.e. acrylic acid, methyle...

Novel biopolymer-based superabsorbent hydrogels were prepared by grafting crosslinked poly(acrylic acid-co-methacrylic acid) chains onto gelatin backbones through a free radical polymerization method. The graft copolymerization reaction was carried out in a homogeneous medium and in the presence of ammonium persulfate (APS) as an initiator and N,N′...

The boundary element method (BEM) is a popular technique to solve engineering problems. We compare the circular arc elements (CAE) discretization to both linear and quadratic discretizations. The main aim of this paper is to determine analytical expressions for the discretization error in 2D BEM for the Laplace equation using CAE discretization. Th...

A novel biopolymer-based superabsorbent hydrogel composite based on kappa-carrageenan (κC) have been prepared via graft copolymerization of acrylic acid (AA) in the presence of bentonite powder using methylenebisacrylamide (MBA) as a crosslinking agent and ammonium persulfate (APS) as an initiator. The hydrogel structure was confirmed using FTIR sp...

Objective: This study investigated the usefulness of a pH-sensitive protein-based hydrogel for in vitro controlled release of cephalexin Methods: The hydrogels were prepared via graft copolymerization of mixtures of acrylic acid (AA) and acrylamide (AAm) onto gelatin backbones by a free radical polymerization technique using ammonium persulfate (AP...

The boundary element method (BEM) is a popular technique to solve engineering problems. We compare the circular arc elements (CAE) discretization to both linear and quadratic discretizations. The main aim of this paper is to determine analytical expressions for the discretization error in 2D BEM for the Laplace equation using CAE discretization. Th...

The solution of Poisson’s equation is essential for many branches of science and engineering such as fluid-mechanics, geosciences, and electrostatics. Solution of two-dimensional Poisson’s equations is carried out by BEM based on Galerkin Vector Method in which the integrals that appear in the boundary element method are expressed by analytical int...

In this paper, a novel protein-based super absorbent hydrogel was synthesized through crosslinking graft copolymerization of methacrylic acid onto collagen, using ammonium persulphate as a free radical initiator in the presence of methylenebisacrylamide as a crosslinker. The hydrogel structure was confirmed by FTIR spectroscopy. We were systematica...

In this work, a novel biopolymer-based superabsorbent hydrogel was synthesized through crosslinking graft copolymerization of 2-hydroxyethyl acrylate (HEA) onto kappa-carrageenan, using potassium persulfate (KPS) as a free radical initiator in the presence of methylene bisacrylamide (MBA) as a crosslinker. The chemical structure of the hydrogels wa...