Natural Convection from a Permeable Sphere Embedded in a Variable Porosity Porous Medium Due to Thermal Dispersion

The laminar natural convection boundary-layer flow of an electricallyconducting fluid from a permeable sphere embedded in a porous medium with variable porosity is considered. The non-Darcy effects including convective, boundary, inertial and thermal dispersion effects are included in this analysis. The sphere surface is maintained at a constant heat flux and is permeable to allow for possible fluid wall suction or blowing. The resulting governing equations are nondimensionalized and transformed into a nonsimilar form and then solved numerically by using the secondlevel local non-similarity method that is used to convert the non-similar equations into a system of ordinary differential equations. Comparisons with previously published work are performed and excellent agreement is obtained. A parametric study of the physical parameters is conducted and a representative set of numerical results for the velocity and temperature profiles as well as the local skin-friction coefficient and the Nusselt number are illustrated graphically to show interesting features of Darcy number, inertia coefficient, the magnetic parameter, dimensionless coordinate, dispersion parameter, the Prantdl number and suction/blowing parameter

Ultrasonographic Differential Diagnosis of Superficial Swellings in Farm Animals

This report describes the ultrasonographic differential diagnosis of different types of swellings affecting (28) farm animals. The swellings were, abscess (11), cyst (2), hematoma (2), hernia (9) and urethral diverticulum (4). The swellings varied sonographically according to the type, duration, content and location. Cases suffering the same type of swellings may have some degree of difference in echogenicity according to the period of the swelling. Abscesses appeared as hypo/hyperechoic structures with distinct hyperechoic well-developed capsule. Recent hematomas were anechoic with a well demarcated wall, with increased duration, the hematoma gradually became more echoic and textured. The hernial ring was determined as a discontinuation of the abdominal wall echogenicity and the hernial contents were clearly evaluated via ultrasonography. Recent cysts resembled hematoma in compartmentalization but the location and case history helped the differential diagnosis. Urethral dilatation appeared sonographically as an anechoic to hypoechoic homogenous structure with well demarcated wall and acoustic enhancement. Ultrasonography could be considered a successful, noninvasive, rapid technique for differential diagnosis of different types of swellings in farm animals. It could be easily used under field conditions to screen the lesions before the surgical operations and to fellow up the cases after surgery

Unsteady slip flow of amicropolarnanofluid over an impulsively stretched vertical surface

The unsteady mixed convective flow of micropolarnanofluid over an impulsively stretched vertical surface has been examined. A model has been developed to analyze the behavior of nanofluids in presentmicropolar fluids studied numerically for both cases of assisting and opposing flow taking into account the thermal convective boundary condition. A model has been developed to analyze the behavior of nanofluids containing metallic nanoparticles as copper (Cu)and nonmetallic nanoparticles as alumina (A  in water-micropolarnanofluidhave been considered. The governing partial differential equations have been transformed to non-similar differential equations then have been solved numerically by using theRunge-Kutta-Fehlberg method of seventh order (RKF7). The results have been compared with the published results and are found in excellent agreement

Mixed Convective Flow of Micropolar Nanofluid across a Horizontal Cylinder in Saturated Porous Medium

The micropolar nanofluids are the potential liquids that enhance the thermophysical features and ability of heat transportation instead of base liquids. Alumina and Titania nanoparticles are mixed in a micropolar fluid. The impact of convective boundary condition is also examined with assisting and opposing flows of both nanofluids. The main objective of this study is to investigate mixed convective flow and heat transfer of micropolar nanofluids across a cylinder in a saturated porous medium. Non-similar variables are used to make the governing equations dimensionless. The local similar and non-similar solutions are obtained by using the Runge-Kutta-Fehlberg method of seventh order. The impacts of various embedded variables on the flow and heat transfer of micropolar nanofluids are investigated and interpreted graphically. It is demonstrated that the skin friction and heat transfer rates depend on solid volume fraction of nanoparticles, Biot number, mixed convection, and material parameters

Unsteady slip flow of amicropolarnanofluid over an impulsively stretched vertical surface

773-782The unsteady mixed convective flow of micropolarnanofluid over an impulsively stretched vertical surface has been examined. A model has been developed to analyze the behavior of nanofluids in presentmicropolar fluids studied numerically for both cases of assisting and opposing flow taking into account the thermal convective boundary condition. A model has been developed to analyze the behavior of nanofluids containing metallic nanoparticles as copper (Cu)and nonmetallic nanoparticles as alumina (A  in water-micropolarnanofluidhave been considered. The governing partial differential equations have been transformed to non-similar differential equations then have been solved numerically by using theRunge-Kutta-Fehlberg method of seventh order (RKF7). The results have been compared with the published results and are found in excellent agreement