a b s t r a c tThe influence of temperature-dependent fluid properties on the hydro-magnetic flow and heat transfer over a stretching surface is studied. The stretching velocity and the transverse magnetic field are assumed to vary as a power of the distance from the origin. It is assumed that the fluid viscosity and the thermal conductivity vary as an inverse function and linear function of temperature, respectively. Using the similarity transformation, the governing coupled non-linear partial differential equations are transformed into coupled non-linear ordinary differential equations and are solved numerically by the Keller-Box method. The governing equations of the problem show that the flow and heat transfer characteristics depend on five parameters, namely the stretching parameter, viscosity parameter, magnetic parameter, variable thermal conductivity parameter, and the Prandtl number. The numerical values obtained for the velocity, temperature, skin friction, and the Nusselt number are presented through graphs and tables for several sets of values of the parameters. The effects of the parameters on the flow and heat transfer characteristics are discussed.

Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases encoded by 24 distinct genes. Their functions have been implicated in numerous normal and pathologic processes, including uterine involution and organogenesis, inflammation and wound healing, vascular and autoimmune disease progression. Pertinent to this review, the role of MMPs in cancer biology is fairly well researched and documented, and remains a subject of continuing intense investigation. Not only are several MMPs overexpressed in head and neck squamous cell carcinomas (HNSCCs), expression has been correlated with salient tumorigenic hallmarks, such as cell proliferation, angiogenesis, invasion, and metastasis. The utility of changes in the expression profile, as well as various MMP polymorphisms as potential prognostic markers in oral cancers and oral premalignant lesions, have been investigated. Furthermore, the potential therapeutic utility of targeting MMPs in cancer remains attractive, although outcomes in this respect appear so far to be less encouraging with respect to HNSCCs. Because of the disappointing results observed in clinical trials where MMP-targeting regimens for HNSCCs utilized broad-spectrum small MMP catalytic site inhibitors, investigators now envision new strategies for MMP-specific targeting based on the recognition of new noncatalytic MMP domains with distinct functions. This review provides an overview of MMP activities in general and in cancers, and an update of their activities in HNSCC. Specifically, their role in the development and progression of HNSCC and their function as signaling molecules is discussed. Finally, their role as potential prognostic biomarkers and therapeutic targets in HNSCC is revisited.

A numerical solution for the steady magnetohydrodynamic (MHD) non-Newtonian powerlaw fluid flow over a continuously moving surface with species concentration and chemical reaction has been obtained. The viscous flow is driven solely by the linearly stretching sheet, and the reactive species emitted from this sheet undergoes an isothermal and homogeneous one-stage reaction as it diffuses into the surrounding fluid. Using a similarity transformation, the governing non-linear partial differential equations are transformed into coupled nonlinear ordinary differential equations. The governing equations of the mathematical model show that the flow and mass transfer characteristics depend on six parameters, namely, the power-law index, the magnetic parameter, the local Grashof number with respect to species diffusion, the modified Schmidt number, the reaction rate parameter, and the wall concentration parameter. Numerical solutions for these coupled equations are obtained by the Keller-Box method, and the solutions obtained are presented through graphs and tables. The numerical results obtained reveal that the magnetic field significantly increases the magnitude of the skin friction, but slightly reduces the mass transfer rate. However, the surface mass transfer strongly depends on the modified Schmidt number and the reaction rate parameter; it increases with increasing values of these parameters. The results obtained reveal many interesting behaviors that warrant further study of the equations related to non-Newtonian fluid phenomena, especially shearthinning phenomena. Shear thinning reduces the wall shear stress.

SUMMARYFinite elements based on Mindlin-Reissner theory and three-dimensional theory are used to study the distribution of shear forces and twisting moments in plates with various simple support conditions. Differences between the results obtained using these two theories are highlighted. A crude adaptive mesh refinement procedure is applied to improve the accuracy of the finite-element analysis.

No abstract

In this investigation, our objective is to study the effect of non-uniform slot suction or injection into a steady mixed convective MHD boundary layer flow over a vertical wedge embedded in a porous medium in the presence of chemical reaction. The wall of the wedge is embedded in a uniform porous medium in order to allow possible fluid wall suction or injection. The surface of the wedge is maintained at a variable wall temperature and concentration. The fluid is assumed to be viscous, incompressible and electrically conducting; and the magnetic field is applied transversally in the direction of the flow. The governing boundary layer equations are transformed into a set of non-similar and non-dimensional equations by using suitable coordinate transformations. Non-similar solutions are obtained numerically by solving coupled non-linear partial differential equations using an implicit finite difference scheme in combination with the quasi-linearization technique. Comparisons with previously published works are performed and excellent agreement between the results is obtained. A parametric study of the physical parameters is conducted and a representative set of numerical results for the velocity, temperature and concentration distributions, as well as the local skin friction coefficient and the local Nusselt and Sherwood numbers are illustrated graphically to show interesting features of the solutions.

No abstract

No abstract