the kinetic of photo oxidative decolorization of c.i. acid yellow 23 (ay23) was investigated in uv/ process. the semi-logarithmic of the concentrations of ay23 versus irradiation time were linear, suggesting pseudo-first order reaction. a simple kinetic model is proposed which confirms pseudo- first order reaction. the results indicate that the apparent reaction rate constant is a function of l...

In this paper, we study the stability of solutions to systems differential equations with discontinuous right-hand sides. We have investigated nonlinear and linear equations. Stability sufficient conditions for are expressed as a logarithmic norm coefficients Jacobian side system Sufficient in terms norms sides (for equations) following advantages: (1) investigating different metrics from same ...

Two discretizations, linear and nonlinear, of basic notions of the complex analysis are considered. The underlying lattice is an arbitrary quasicrystallic rhombic tiling of a plane. The linear theory is based on the discrete Cauchy-Riemann equations, the nonlinear one is based on the notion of circle patterns. We clarify the role of the rhombic condition in both theories: under this condition t...

In this article we decide to define a modified homotopy perturbation for solving non-linear integral equations. Almost, all of the papers that was presented to solve non-linear problems by the homotopy method, they used from two non-linear and linear operators. But we convert a non-linear problem to two suitable non-linear operators also we use from appropriate bases functions such as Legendre ...

We present an iterative algorithm for solving a class of nonlinear Laplacian system of equations in Õ(km log(kn/ǫ)) iterations, where k is a measure of nonlinearity, n is the number of variables, m is the number of nonzero entries in the graph Laplacian L, ǫ is the solution accuracy and Õ() neglects (non-leading) logarithmic terms. This algorithm is a natural nonlinear extension of the one by o...

in this paper, the numerical technique based on hybrid bernoulli and block-pulse functions has been developed to approximate the solution of system of linear volterra integral equations. system of volterra integral equations arose in many physical problems such as elastodynamic, quasi-static visco-elasticity and magneto-electro-elastic dynamic problems. these functions are formed by the hybridi...

The method of one parameter, point symmetric, approximate Lie group invariants is applied to the problem of determining solutions of systems of pure one-dimensional, diffusion equations. The equations are taken to be non-linear in the dependent variables but otherwise homogeneous. Moreover, the matrix of diffusion coefficients is taken to differ from a constant matrix by a linear perturbation w...