Convection – Diffusion – Radiation Heat and Mass Transfer to a Sphere Accompanied by a Surface Exothermal Chemical Reaction

The steady-state, coupled heat and mass transfer from a fluid flow to a sphere accompanied by an exothermal catalytic chemical reaction on the surface of the sphere is analysed taking into consideration the effect of thermal radiation. The flow past the sphere is considered steady, laminar and incompressible. The radiative transfer is modeled by P0 and P1 approximations. The mathematical model equations were discretized by the finite difference method. The discrete equations were solved by the defect correction – multigrid method. The influence of thermal radiation on the sphere surface temperature, concentration and reaction rate was analysed for three parameter sets of the dimensionless reaction parameters. The numerical results show that only for very small values of the Prater number the effect of thermal radiation on the surface reaction is not significant.

Effects of temperature dependent viscosity and thermal conductivity on natural convection flow along a curved surface in the presence of exothermic catalytic chemical reaction

The natural convection boundary layer flow of a viscous incompressible fluid with temperature dependent viscosity and thermal conductivity in the presence of exothermic catalytic chemical reaction along a curved surface has been investigated. The governing non dimensional form of equations is solved numerically by using finite difference scheme. The numerical results of velocity profile, temperature distribution and mass concentration as well as for skin friction, heat transfer rate and mass transfer rate are presented graphically and in tabular form for various values of dimensionless parameters those are generated in flow model during dimensionalization. From the obtained results, it is concluded that the exothermic catalytic chemical reactions is associated with temperature dependent viscosity and thermal conductivity. Further, it is concluded that the body shape parameter also plays an important quantitative role for change in velocity profile, temperature field and mass concentration behavior in the presence of exothermic catalytic chemical reaction.

Mixed convection flow along a curved surface in the presence of exothermic catalytic chemical reaction

In the current study, the attention is paid on the phenomena of mixed convection flow under the effect of exothermic catalytic chemical reaction along the curved surface. The proposed problem is modeled in nonlinear coupled partial differential equations. In keeping view the principle of homogeneity the dimensional flow model is transformed into dimensionless by using an appropriate scaling. This well arranged form of equations is then discretized with the aid of finite difference method for the numerical solution. The solutions of the considered model are estimated and displayed in the graphs. Here, in the contemporary study variables of physical significance such as velocity profile, temperature distribution and mass concentration are encountered efficiently. The incorporated pertinent dimensionless numbers that is body shape parameter, mixed convection parameter, modified mixed convection parameter, Prandtle number, exothermic parameter, chemical reaction parameter, temperature relative parameter, dimensionless activation energy parameter, and Schmidt number for which variations in the concentrated physical variables are estimated and presented in graphical way. For each boundary conditions computations are performed along the curved surface for different body shape parameter (n) values range from 0 up to 0.5; the obtained results satisfied by the boundary conditions. The velocity profile becomes increasingly more significant for n equal to 1 and due to the uniformly heated surface temperature profile and mass concentration are uniformly distributed.

Catalysis on Nanostructured Indium Tin Oxide Surface for Fast and Inexpensive Probing of Antibodies during Pandemics

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has become a global threat to human health and the economy. Society needs inexpensive, fast, and accurate quantitative diagnostic tools. Here, we report a new approach using a solid-state biosensor to measure antibodies, which does not require functionalization, unlike conventional biosensors. A nanostructured semiconductor surface with catalytic properties was used as a transducer for rapid immobilization and measurement of the antibody. The transducer response was based on solid-state electronics properties. The changes on the surface of the semiconductor induced changes in the direct current (DC) surface resistivity. This was a result of a catalytic chemical reaction on that surface. This new low-cost approach reduced the response time of the measurement significantly, and it required only a very small amount of sample on the microliter scale.

The Effect of Thermal Radiation on the Surface Catalytic Chemical Reaction

The effect of thermal radiation on the two - dimensional, steady-state, coupled heat and mass transfer from a fluid flow to a sphere in the presence of an exothermal catalytic chemical reaction on the surface of the sphere is investigated in the present work. The P1 approximation models the radiative transfer. The finite difference method was used to discretize the mathematical model equations. The discrete equations were solved by the defect correction - multigrid method. The influence of thermal radiation on the sphere surface temperature, concentration and reaction rate was analysed. It was found that, for high values of the radiation conduction parameter, thermal radiation has a significant effect on the surface reaction.

Modeling and analysis of the impact of exothermic catalytic chemical reaction and viscous dissipation on natural convection flow driven along a curved surface

The impact of exothermic catalytic chemical reaction and viscous dissipation on natural-convection heat transfer along the curved shape is investigated. In this study, the trend of exothermic catalytic chemical reaction has been introduced in the energy and mass concentration equation. Furthermore, the tangential compo?nent of acceleration due to gravity, gx, as buoyancy force has coupled in momentum equation describe the curved shape. The flow model of the problem is formulated in terms of coupled non-linear PDE together with suitable boundary conditions. From the numerical solutions of the governing equations, it is found that velocity field, temperature distribution and the mass concentration is associated with the dimensionless parameters involved in the flow model. The novelty of the current study is that the characteristics of heat and fluid-flow mechanism are specifically associated with the different values of index parameter n.

Modeling and analysis of the impact of exothermic catalytic chemical reaction and viscous dissipation on natural convection flow driven along a curved surface

The impact of exothermic catalytic chemical reaction and viscous dissipation on natural-convection heat transfer along the curved shape is investigated. In this study, the trend of exothermic catalytic chemical reaction has been introduced in the energy and mass concentration equation. Furthermore, the tangential compo?nent of acceleration due to gravity, gx, as buoyancy force has coupled in momentum equation describe the curved shape. The flow model of the problem is formulated in terms of coupled non-linear PDE together with suitable boundary conditions. From the numerical solutions of the governing equations, it is found that velocity field, temperature distribution and the mass concentration is associated with the dimensionless parameters involved in the flow model. The novelty of the current study is that the characteristics of heat and fluid-flow mechanism are specifically associated with the different values of index parameter n.

Localized catalysis driven by the induction heating of magnetic nanoparticles

Heat generated from magnetic nanoparticles when placed in an alternating magnetic field is used to drive a catalytic chemical reaction.