Abstract The purpose of this article is to formulate a simplified nonlinear fractional mathematical model illustrate the dynamics new coronavirus (COVID-19). Based on infectious characteristics COVID-19, population divided into five compartments: susceptible S ( t ), asymptomatic infection I unreported symptomatic U reported infections W T ) and recovered R collectively referred as (SIUWR). exi...

In this paper, we present a mathematical model for the study of resistance to tuberculosis treatment using fractional derivatives in Caputo sense. This takes into account relationship between Tuberculosis, HIV/AIDS, and diabetes differentiates cases MDR-TB (multidrug-resistant tuberculosis) XDR-TB (extensively drug-resistant tuberculosis). We basic results associated with behavior disease-free ...

The main metabolism of yeasts produces bioethanol. Bioethanol, which is produced from biomass and bioenergy crops, has been promoted as one the most viable alternatives to fossil fuels. following reaction represents all knowledge we have regarding intracellular reactions their regulatory mechanisms: biomass+substrates→ethanol+biomass(morecells). Atangana suggested new operators based on a combi...

The basic ideas of semi-implicit time differencing are reviewed, including analytical results not widely referenced in the meteorological literature. It is shown that solving the resulting implicit equations by simple fixed-point iteration requires a relatively small time step to guarantee convergence, thus defeating the purpose of the semiimplicit method. In contrast, classical iteration metho...

In this paper, we present a novel second order in time mixed finite element scheme for the Cahn-Hilliard-Navier-Stokes equations with matched densities. The scheme combines a standard second order Crank-Nicholson method for the Navier-Stokes equations and a modification to the Crank-Nicholson method for the Cahn-Hilliard equation. In particular, a second order Adams-Bashforth extrapolation and ...

We propose and study two second-order in time implicit-explicit (IMEX) methods for the coupled Stokes-Darcy system that governs flows in karst aquifers. The first is a combination of a second-order backward differentiation formula and the second-order Gear’s extrapolation approach. The second is a combination of the second-order Adams-Moulton and second-order Adams-Bashforth methods. Both algor...

This paper analyzes a number of high-order and optimized finite-difference methods for numerically simulating the propagation and scattering of linear waves, such as electromagnetic, acoustic, and elastic waves. The spatial operators analyzed include compact schemes, noncompact schemes, schemes on staggered grids, and schemes which are optimized to produce specific characteristics. The time-mar...

In this paper we developed accurate finite element methods for solving 3-D Poisson-Nernst-Planck (PNP) equations with singular permanent charges for electrodiffusion in solvated biomolecular systems. The electrostatic Poisson equation was defined in the biomolecules and in the solvent, while the Nernst-Planck equation was defined only in the solvent. We applied a stable regularization scheme to...