This study explains the entropy process of natural convective heating in the nanofluid-saturated cavity in a heated fin andmagnetic field.The temperature is constant on the Y-shaped fin,insulating the topwall while th...This study explains the entropy process of natural convective heating in the nanofluid-saturated cavity in a heated fin andmagnetic field.The temperature is constant on the Y-shaped fin,insulating the topwall while the remaining walls remain cold.All walls are subject to impermeability and non-slip conditions.The mathematical modeling of the problem is demonstrated by the continuity,momentum,and energy equations incorporating the inclined magnetic field.For elucidating the flow characteristics Finite ElementMethod(FEM)is implemented using stable FE pair.A hybrid fine mesh is used for discretizing the domain.Velocity and thermal plots concerning parameters are drawn.In addition,a detailed discussion regarding generation energy by monitoring changes in magnetic,viscous,total,and thermal irreversibility is provided.In addition,line graphs are created for the u and v components of the velocity profile to predict the flow behavior.Current simulations assume the dimensionless representative of magnetic field Hartmann number Ha between 0 and 100 and a magnetic field inclination between 0 and 90 degrees.A constant 4% volume proportion of nanoparticles is employed throughout all scenarios.展开更多
The effects of axisymmetric flow of a Powell-Eyring fluid over an impermeable radially stretching surface are presented. Characteristics of the heat transfer process are analyzed with a more realistic condition named ...The effects of axisymmetric flow of a Powell-Eyring fluid over an impermeable radially stretching surface are presented. Characteristics of the heat transfer process are analyzed with a more realistic condition named the convective boundary condition. Governing equations for the flow problem are derived by the boundary layer approximations. The modeled highly coupled partial differential system is converted into a system of ordinary differential equations with acceptable similarity transformations. The convergent series solutions for the resulting system are constructed and analyzed. Optimal values are obtained and presented in a numerical form using an optimal homotopy analysis method （OHAM）. The rheological characteristics of different parameters of the velocity and temperature profiles are presented graphically. Tabular variations of the skin friction coefficient and the Nusselt number are also calculated. It is observed that the temperature distribution shows opposite behavior for Prandtl and Biot numbers. Furthermore, the rate of heating/cooling is higher for both the Prandtl and Biot numbers.展开更多
The present paper addresses the megnetohydrodynamic Jeffrey fluid flow with heat and mass transfer on an infinitely rotating upright cone. Inquiry is carried out with heat source/sink and chemical reaction effects.Fur...The present paper addresses the megnetohydrodynamic Jeffrey fluid flow with heat and mass transfer on an infinitely rotating upright cone. Inquiry is carried out with heat source/sink and chemical reaction effects.Further, constant thermal and concentration flux situations are imposed. Optimal homotopy analysis method (OHAM) is employed to achieve series solutions of the concerned differential equations. Important results of the flow phenomena are explored and deliberated by means of graphs and numerical tables. It is perceived that thermal boundary layer thickness possess contrast variations for the heat source and heat sink, respectively. The chemical reaction enhances the heat transfer rate but decline the mass transfer rate. Moreover, the precision of the existing findings is verified by associating them with the previously available work.展开更多
Molybdenum is nitrided by a 100-Hz pulsed DC glow discharge technique for various time durations and fill gas pressures to study the effects on the surface properties of molybdenum. X-ray diffractometry （XRD）, scann...Molybdenum is nitrided by a 100-Hz pulsed DC glow discharge technique for various time durations and fill gas pressures to study the effects on the surface properties of molybdenum. X-ray diffractometry （XRD）, scanning electron microscopy （SEM）, and atomic force microscopy （AFM） are used for the structural and morphological analysis of the nitrided layers. Vickers＇ microhardness tester is utilized to investigate surface microhardness. Phase analysis shows the formation of more molybdenum nitride molecules for longer nitriding durations at fill gas pressures of 2 mbar and 3 mbar （1 bar = 105 Pa）. A considerable increase in surface microhardness （approximately by a factor of 2） is observed for longer duration （10 h） and 2-mbar pressure. Longer duration （10 h） and 2-mbar fill gas pressure favors the formation of homogeneous, smooth, hard layers by the incorporation of more nitrogen.展开更多
The effect of the thermal treatment of waste oyster(Crassostrea belcheri)shells on different properties was explored.In this preliminary work,the waste oyster shells were collected from Muar River,Malaysia.All samples...The effect of the thermal treatment of waste oyster(Crassostrea belcheri)shells on different properties was explored.In this preliminary work,the waste oyster shells were collected from Muar River,Malaysia.All samples were cleaned,dried,and subjected to a simple heat treatment in air at 500–1200°C.All heat-treated samples were characterized to determine their mass loss,chemical composition,crystalline phase,surface morphology,and powder density properties.Changing the temperature from 500 to 1200°C increases the calcium(Ca)food content in oyster shells.Furthermore,the decomposition of calcium carbonate(CaCO_(3))from 98.15 wt.%to 99.07 wt.%was completed at 682°C with 45 wt.%mass loss in a controlled nitrogen environment.When heat treatment processes are conducted in air,only 14.74 wt.%mass loss is recorded.The X-ray diffraction results confirmed that CaCO_(3) successfully transformedαpeak(CaO_(4))toγpeak andηpeak(CaO)at an angle(θ)of 30°and at above 800°C.The Fourier transform infrared(FTIR)Result revealed changes in functional groups as the temperature increased.The phase transformation and morphological analysis agree with measured powder density values from 2.63 to 2.30 g·cm^(−3).All these findings indicate that heated waste oyster shells are a potential source of calcium minerals and can be used for biomaterial products.展开更多
In the present study we have explored the time dependent combined convectional flow on a rotating cone in a rotating Jeffrey fluid with the combined effects of heat and mass transfer.The governing equations of motion,...In the present study we have explored the time dependent combined convectional flow on a rotating cone in a rotating Jeffrey fluid with the combined effects of heat and mass transfer.The governing equations of motion,energy and mass transfer for unsteady flow are presented and simplified using similar variables.The reduced coupled nonlinear differential equations are solved analytically with the help of strong analytical technique homotopy analysis method.The heat transfer analysis for prescribed wall temperature is considered.Numerical results for Nusselt number and Sherwood number have computed and discussed.The physical features of pertinent parameters are discussed by plotting the graphs of velocity,heat transfer,concentration,skin friction,Nusselt number and Sherwood number.展开更多
文摘This study explains the entropy process of natural convective heating in the nanofluid-saturated cavity in a heated fin andmagnetic field.The temperature is constant on the Y-shaped fin,insulating the topwall while the remaining walls remain cold.All walls are subject to impermeability and non-slip conditions.The mathematical modeling of the problem is demonstrated by the continuity,momentum,and energy equations incorporating the inclined magnetic field.For elucidating the flow characteristics Finite ElementMethod(FEM)is implemented using stable FE pair.A hybrid fine mesh is used for discretizing the domain.Velocity and thermal plots concerning parameters are drawn.In addition,a detailed discussion regarding generation energy by monitoring changes in magnetic,viscous,total,and thermal irreversibility is provided.In addition,line graphs are created for the u and v components of the velocity profile to predict the flow behavior.Current simulations assume the dimensionless representative of magnetic field Hartmann number Ha between 0 and 100 and a magnetic field inclination between 0 and 90 degrees.A constant 4% volume proportion of nanoparticles is employed throughout all scenarios.
文摘The effects of axisymmetric flow of a Powell-Eyring fluid over an impermeable radially stretching surface are presented. Characteristics of the heat transfer process are analyzed with a more realistic condition named the convective boundary condition. Governing equations for the flow problem are derived by the boundary layer approximations. The modeled highly coupled partial differential system is converted into a system of ordinary differential equations with acceptable similarity transformations. The convergent series solutions for the resulting system are constructed and analyzed. Optimal values are obtained and presented in a numerical form using an optimal homotopy analysis method （OHAM）. The rheological characteristics of different parameters of the velocity and temperature profiles are presented graphically. Tabular variations of the skin friction coefficient and the Nusselt number are also calculated. It is observed that the temperature distribution shows opposite behavior for Prandtl and Biot numbers. Furthermore, the rate of heating/cooling is higher for both the Prandtl and Biot numbers.
文摘The present paper addresses the megnetohydrodynamic Jeffrey fluid flow with heat and mass transfer on an infinitely rotating upright cone. Inquiry is carried out with heat source/sink and chemical reaction effects.Further, constant thermal and concentration flux situations are imposed. Optimal homotopy analysis method (OHAM) is employed to achieve series solutions of the concerned differential equations. Important results of the flow phenomena are explored and deliberated by means of graphs and numerical tables. It is perceived that thermal boundary layer thickness possess contrast variations for the heat source and heat sink, respectively. The chemical reaction enhances the heat transfer rate but decline the mass transfer rate. Moreover, the precision of the existing findings is verified by associating them with the previously available work.
基金supported by the Higher Education Commission (HEC) of Pakistan under a research project
文摘Molybdenum is nitrided by a 100-Hz pulsed DC glow discharge technique for various time durations and fill gas pressures to study the effects on the surface properties of molybdenum. X-ray diffractometry （XRD）, scanning electron microscopy （SEM）, and atomic force microscopy （AFM） are used for the structural and morphological analysis of the nitrided layers. Vickers＇ microhardness tester is utilized to investigate surface microhardness. Phase analysis shows the formation of more molybdenum nitride molecules for longer nitriding durations at fill gas pressures of 2 mbar and 3 mbar （1 bar = 105 Pa）. A considerable increase in surface microhardness （approximately by a factor of 2） is observed for longer duration （10 h） and 2-mbar pressure. Longer duration （10 h） and 2-mbar fill gas pressure favors the formation of homogeneous, smooth, hard layers by the incorporation of more nitrogen.
基金financial support under the UTHM contract grant H518
文摘The effect of the thermal treatment of waste oyster(Crassostrea belcheri)shells on different properties was explored.In this preliminary work,the waste oyster shells were collected from Muar River,Malaysia.All samples were cleaned,dried,and subjected to a simple heat treatment in air at 500–1200°C.All heat-treated samples were characterized to determine their mass loss,chemical composition,crystalline phase,surface morphology,and powder density properties.Changing the temperature from 500 to 1200°C increases the calcium(Ca)food content in oyster shells.Furthermore,the decomposition of calcium carbonate(CaCO_(3))from 98.15 wt.%to 99.07 wt.%was completed at 682°C with 45 wt.%mass loss in a controlled nitrogen environment.When heat treatment processes are conducted in air,only 14.74 wt.%mass loss is recorded.The X-ray diffraction results confirmed that CaCO_(3) successfully transformedαpeak(CaO_(4))toγpeak andηpeak(CaO)at an angle(θ)of 30°and at above 800°C.The Fourier transform infrared(FTIR)Result revealed changes in functional groups as the temperature increased.The phase transformation and morphological analysis agree with measured powder density values from 2.63 to 2.30 g·cm^(−3).All these findings indicate that heated waste oyster shells are a potential source of calcium minerals and can be used for biomaterial products.
文摘In the present study we have explored the time dependent combined convectional flow on a rotating cone in a rotating Jeffrey fluid with the combined effects of heat and mass transfer.The governing equations of motion,energy and mass transfer for unsteady flow are presented and simplified using similar variables.The reduced coupled nonlinear differential equations are solved analytically with the help of strong analytical technique homotopy analysis method.The heat transfer analysis for prescribed wall temperature is considered.Numerical results for Nusselt number and Sherwood number have computed and discussed.The physical features of pertinent parameters are discussed by plotting the graphs of velocity,heat transfer,concentration,skin friction,Nusselt number and Sherwood number.
