This paper developed a simple but accurate automation tool for quick design of gating and riser systems for green sand iron castings. Codes for calculation of gating elements’ parameters were generated in MATLAB from standard fluid mechanics and empirical formulae. Guided Users’ Interfaces (GUIs) were developed to guide the users in the use of the tool. The package was validated with shop floor trials using the tool developed to generate and design gating and riser systems for some grey iron components. These components were moulded in green sand, cast and evaluated using visual inspection, bulk density and apparent porosity measurement and ultrasonic flaw detection methods. The results of evaluation revealed castings free from any form of gating related defects.
The effect of viscous dissipation and temperature dependent viscosity on MHD free convection flow over a sphere with heat conduction has been analyzed in the article. The governing equations are transformed into dimensionless non-similar equations by using a set of useful transformations and solved numerically by finite difference method along with Newton’s linearization approximation. Attention has been focused on the evaluation of shear stress in terms of local skin friction and local Nusselt number, the velocity and the temperature profiles over the whole boundary layer are shown graphically by using Tecplot-10 and tabular form for different values of the Prandtl’s number Pr, magnetic parameter M, the temperature dependent viscosityε, viscous dissipation parameter N and the Joule heating parameter J.
In this paper, the formulation of the block second derivative Blended Linear Multistep methods for step numbers k=5,6 and7 was considered. We present a new family of blended block A-stable second derivative linear multistep methods of order p=k+2 for step numbers k=5,6 and 7 for the solution of stiff initial value problems. The newly constructed blended block methods are all A-stable, consistent, zero-stable and as such convergent. Numerical examples are considered to show the performance of the new methods.
In this paper, we introduce the notion of fuzzy soft G-metric space via fuzzy soft elements. Then, fuzzy soft convergence and fuzzy soft continuity are studied in fuzzy soft G-metric space. Finally, some fixed points theorems are proved.
A treatment strategy for the total eradication of human immunodeficiency virus (HIV) in infected individuals is presently not feasible. However, the adoption of highly-active antiretroviral therapy (HAART) has been effective in managing HIV/AIDS infected patients in recent times. In this paper, a deterministic mathematical model is proposed and used to monitor the interactions between uninfected CD4+ T-cells, Infected CD4+ T-cells, CD8+ T-cells, infectious virus and immature non-infectious virus in the course of in-host HIV cellular dynamics. The goal is to find the adequate combination of the treatment regimens that will minimize the treatment systemic costs as well as deliver maximal health benefits to the HIV-positive patients. The model analyses show that the model disease-free equilibrium is locally and globally asymptotically stable if the basic reproduction number is less than unity. Thereafter, the proposed model is solved numerically and the result simulated for different combinations of the two common antiretroviral drugs effectiveness. Finding from the simulations show that treatment outcome would depend largely on patient’s HIV/AIDS status indicators before initiating treatment and his/her antiretroviral therapy history.