In this paper, the bioconvective flow in a porous square cavity containing oxytactic microorganism in the presence of chemical reaction is investigated. The bioconvection flow and heat transfer in porous media are formulated based on the Darcy model of Boussinesq approximation. The governing partial differential equations are solved using the Galerkin finite element method. The computational nu...

polyethylene imide was synthesized from the reaction of high density polyethylene grafted maleic anhydride (pe-g-ma) and 1,4-diaminobutane in boiling xylene. the chemical compositions of the reaction products were examined by fourier transform infrared spectroscopy. different conditions and parameters like the effect of temperature, time, monomer concentration and oxygen on the extent of reacti...

This article presents the heat and mass transfer characteristics of unsteady MHD flow of a viscous, incompressible and electrically conducting micropolar fluid in the presence of viscous dissipation and radiation over a porous stretching sheet with chemical reaction. The governing partial differential equations (PDEs) are reduced to ordinary differential equations (ODEs) by applying suitable si...

This numerical study investigates the steady state unimolecular thermal decomposition of a chemical dissolved in water inside a parallel-plate reactor containing four heated circular rods using a penalty Galerkin finite element approach. The reactant fluid enters from the left inlet and exits from the right outlet of the reactor. All solid walls of the reactor are assumed to be thermodynamicall...

Evaluation of thermal stability and runaway behavior of any exothermic chemical system is of great importance for the design and operation of a chemical process. The evaluation process should be based on a thorough investigation of the reaction chemistry including reaction pathways, thermodynamic, and kinetic parameters. When addressing the reactivity hazards of any reacting system, the dominan...

Autocatalytic reactions may propagate as solitary waves, namely, at a constant front velocity and with a stationary concentration profile, resulting from a balance between molecular diffusion and chemical reaction. When the reaction is exothermic, a thermal wave is linked to the chemical front. As the thermal diffusivity is nearly two orders of magnitude larger than the molecular one, the tempe...

Molecular motors operate in an environment dominated by viscous friction and thermal fluctuations. The chemical reaction in a motor may produce an active force at the reaction site to directly move the motor forward. Alternatively a molecular motor may generate a unidirectional motion by rectifying thermal fluctuations using free energy barriers established in the chemical reaction. The reactio...

We report the thermal degradation of a solid film of polypropylene carbonate, driven by the photothermal effect of gold nanoparticles. We provide characterization of the products of this chemical reaction and use the known activation barrier for this chemical reaction to discuss the temperatures obtained in the film. In addition, we report the efficiency of the reaction as a function of nanopar...

Keywords: Hopscotch scheme Thermal explosion Nonlinear source term Linear stability analysis a b s t r a c t Numerical solutions to the Frank-Kamenetskii partial differential equation modelling a thermal explosion in a cylindrical vessel are obtained using the hopscotch scheme. We observe that a nonlinear source term in the equation leads to numerical difficulty and hence adjust the scheme to a...