Journal of the Nigerian Mathematical Society最新文献

This research work entails the study of the existence of common fixed points of some Ciric classes of contractive mappings in cone $b$-metric spaces. The main result obtained unifies, improves and generalizes several results in literature including those of Abbas et al. (2010) and Huang and Xu (2012). Furthermore, as a way of applications, the result is used to discuss common coupled, tripled and multipled fixed points of contractive maps defined on cone $b$-metric spaces, via product cone $b$-metric spaces.

Technique of orthogonal collocation along with finite elements has been presented to solve the linear and non linear heat conduction problems numerically. Choice of Lagrangian interpolation polynomials as base function has been opted to discretize the trial function. Error analysis has been discussed in terms of element size for both the linear and non linear problems. Proposed technique has been applied on different types of linear and non linear heat conduction problems and the numerical values are plotted using 2D and 3D graphs.

The primary focus of this work is to numerically investigate the influence of temperature dependent viscosity and thermal conductivity on hydromagnetic flow over slendering stretching sheet. In the process held at high temperature like glass blowing, the fluid properties like viscosity and thermal conductivity may gets influenced in such temperature which motivated us to analyze those kind of problem. Considering steady, two dimensional, nonlinear, laminar flow of an incompressible, viscous and electrically conducting fluid over a stretching sheet with variable thickness in the presence of variable magnetic field. Numerical computations are carried out for various values of the physical parameters and the effects over the velocity and temperature are analyzed. Numerical values of dimensionless skin friction coefficient and non-dimensional rate of heat transfer are also obtained and presented in tabulated form. It is noticed that, in additional to the magnetic field there are two more regulators which can manipulate to maintain the optimal heat for the glass blowing process to attain required shapes.

In this paper, we put restrictions on the coefficients of a polynomial in order to improve the bounds for their zeros in a specific region. Our results extend and generalise a number of previously well known theorems including Eneström–Kakeya theorem.

Steady two-dimensional non-Newtonian second grade fluid is studied under the influence of temperature dependent viscosity and thermal conductivity. The viscosity is assumed to vary inversely as linear function of temperature while the thermal conductivity varies directly as linear function of temperature. Also, effects of radiative heat, viscous dissipation and heat source/sink are considered in the energy equation. The basic governing partial differential equations for the velocity and temperature are transformed to ordinary differential equations (ODEs) using appropriate similarity variables. These coupled nonlinear ODEs have been solved approximately subject to appropriate boundary conditions by Runge–Kutta shooting technique. The quantitative effects of emerging dimensionless physical parameters on the velocity, temperature, skin friction and heat transfer rate are displayed graphically. The numerical investigation of the variable thermo-physical properties of a second grade fluid over a stretching sheet provides an extension to previous work.

In this paper we present some existence results for a fourth order multipoint boundary value problem at resonance. Our main tools are based on the coincidence degree theory of Mawhin.

This paper deals with the triangular points $L_{4,5}$ of the relativistic restricted three-body problem (R3BP) when the smaller primary is assumed triaxial. It is noticed that the locations and stability of the triangular points are affected by both relativistic and triaxiality pertubations. It can be easily seen that the range of stability region of these points is reduced by the effects of relativistic and triaxiality factors and more especially decreases with the increase of triaxiality factor.

Analytic expression for unsteady hydromagnetic boundary layer flow past an oscillating vertical plate in optically thick nanofluid in presence of thermal radiation and uniform transverse magnetic field is obtained. The Rosseland diffusion flux model is adopted to simulate thermal radiation effects. The momentum and energy conservation equations are made dimensionless and analytic solution is obtained using the Laplace transform. The results for velocity and temperature are obtained and plotted graphically. It is found that the velocity of the nanofluid increases with radiation parameter Nr, Grashof number Gr and time while decreases with increase in magnetic field and Prandtl number Pr. Temperature of nano-fluids increases with time while decrease with increase in Nr and Pr.

This paper investigates the problem of MHD boundary layer flow and heat transfer of an electrically conducting dusty fluid over an unsteady stretching surface through a non-Darcy porous medium. The flow in porous medium is described by employing the Darcy–Forchheimer based model. The unsteadiness in the flow and temperature fields are because of time-dependent stretching velocity and surface temperature. The effect of thermal radiation, viscous dissipation and non-uniform heat source/sink are also taken into account. The pertinent time-dependent equations, governing the flow and heat transfer are reduced into a set of non-linear ordinary differential equations with the aid of suitable similarity transformations. The transformed equations are numerically integrated using fourth–fifth order Runge–Kutta–Fehlberg method. The effects of various physical parameters on the velocity and temperature profiles of both phases are analyzed through several plots. Obtained numerical results are compared and found to be in good agreement with previously published results as special cases of the present investigation. It is found that, by suspending fine dust particles in the clean fluid reduces the thermal boundary layer thickness. Therefore, the dusty fluids are preferable in engineering and scientific applications, involving cooling processes.

In this paper, an explicit Exponential Method (EM), which is an off-shoot of Jibunoh’s spectral decomposition is developed for the accurate and automatic integration of nonlinear (stiff and nonstiff) ODE systems. In particular, the Vanderpol system of equations is solved. The method is also applicable to linear systems, including linear oscillatory systems or systems with complex eigenvalues. It has simplicity of implementation by automatic computation using the QBASIC Codes and produces high accuracy or the exact theoretical solutions in any nonlinear or linear systems. The EM is, therefore, superior to many traditional methods which are less accurate and which integrate nonlinear systems with cumbersome procedures.