ethylene was homopolymerized over ziegler-natta catalyst and the homopolymerization was modeled using moment equations. mechanism was modeled according to five different reaction centers of catalyst. for each center, there are different reaction rate coefficients; therefore the final product of each center would be expected to be different. modeling results showed good conformity to the experim...

in this paper, we conduct a comparative study between the homotopy perturbation method (hpm) and adomian’s decomposition method (adm) for analytic treatment of nonlinear volterra integral equations, and we show that the hpm with a specific convex homotopy is equivalent to the adm for these type of equations.

‎we study dual integral equations which appear in formulation of the‎ ‎potential distribution of an electrified plate with mixed boundary‎ ‎conditions‎. ‎these equations will be converted to a system of‎ ‎singular integral equations with cauchy type kernels‎. ‎using‎ ‎chebyshev polynomials‎, ‎we propose a method to approximate the‎ ‎solution of cauchy type singular integral equation which will ...

in this paper, a positive definite semi-discrete mixed finite element method was presented for two-dimensional parabolic equations. in the new positive definite systems, the gradient equation and flux equations were separated from their scalar unknown equations.  also, the existence and uniqueness of the semi-discrete mixed finite element solutions were proven. error estimates were also obtaine...

in this paper, an application of homotopy perturbation method is appliedto nding the solutions of the seven-order sawada-kotera (ssk) and a lax'sseven-order kdv (lskdv) equations. then obtain the exact solitary-wave so-lutions and numerical solutions of the ssk and lskdv equations for the initialconditions. the numerical solutions are compared with the known analyticalsolutions. their rem...

the kinetics of zn sorption by ten calcareous soils of iran were measured and fitted to several equations (zero-, first-, second-, third-order, parabolic diffusion, simple elovich, and exponential equations). two initial concentrations of zinc i.e. 20 and 80 mg zn l-1 were used and observations were carried out for 100 hours. the time required to reach the near equilibrium state was about 24 ho...

in this paper, some applications of the method of least squares (mls) for the solution of various problems in electromagnetics engineering is briefly reviewed. here, mls is employed for the solution of various problems such as solution of equations, curve fitting to measured data, generalized fourier coefficients, linear operator equations, inegro-differential equations, electrostatics and magn...

A beautiful and influential subject in the study of the question of smoothness of solutions for the Navier – Stokes equations in three dimensions is the theory of partial regularity. A major paper on this topic is Caffarelli, Kohn & Nirenberg [5](1982) which gives an upper bound on the size of the singular set S(u) of a suitable weak solution u. In the present paper we describe a complementary ...

the spline collocation method  is employed to solve a system of linear and nonlinear fredholm and volterra integro-differential equations. the solutions are collocated by cubic b-spline and the integrand is approximated by the newton-cotes formula. we obtain the unique solution for linear and nonlinear system $(nn+3n)times(nn+3n)$ of integro-differential equations. this approximation reduces th...