this paper a novel homotopy perturbation method has been presented for forced convection boundary layer problems in a porous medium. Noting the infinite condition, a homotopy form which is similar to the singular perturbation form has been considered. The inner and outer solutions have been achieved and the coincidence of the results has been investigated with a proper matching method. The resu...

Azoospermia is one of the challenging disorders affecting couples who are afflicted with infertility. Human testisderivedcells (hTCs) are suitable candidates for the initiation of in-vitro spermatogenesis for these types of patients.The current study aimed to assess the proliferation of hTCs through the cell culture on the three-dimensional (3D) porousscaffolds. Cells harveste...

Background: In the present study, a tissue engineered silk fibroin (SF) scaffold containing simvastatin-loaded silk fibroin nanoparticles (SFNPs) were used to stimulate the regeneration of the defected bone. Methods: At first, the porous SF scaffold was prepared using freeze-drying. Then simvastatin-loaded SFNPs were made by dissolvation method and embedded in the SF scaffold. Afterwards, the ...

A three-dimensional selenium solar cell with the structure of Au/Se/porous TiO2/compact TiO2/fluorine-doped tin oxide-coated glass plates was fabricated by an electrochemical deposition method of selenium, which can work for the extremely thin light absorber and the hole-conducting layer. The effect of experimental conditions, such as HCl and H2SeO3 in an electrochemical solution and TiO2 parti...

A simple method for fabrication of highly ordered gold nanorod film is introduced in this article. The procedure is based on thermal evaporation of gold into a porous anodic alumina film (PAA). The PPA film was fabricated by combining the hard and mild anodization. This combination effectively decreases the processing time of fabrication of highly ordered porous anodic alumina film with c...

In this study, we present a model based on the “second-order” nonlinear homogenization method for estimating the macroscopic response and the evolution of microstructure in two-dimensional viscoplastic porous media. The estimates of the new model are compared with unit cell finite element calculations and the earlier “variational” nonlinear homogenization method. The three methods are compared ...

To reduce the noise and vibration perturbations, it is beneficial to use the dissipative properties of poroelastic materials. These materials are generally not used alone, but rather inserted in composite mechanical assemblies made of elastic structures, poroelastic materials and air insertions. If these structures are assemblies of layers of materials, they are called multilayer complexes. If ...

Porous PEEK structures with approximately 85% open porosity have been made using PEEKOPTIMA® powder and a particulate leaching technique using porous, near-spherical, sodium chloride beads. A novel manufacturing approach is presented and compared with a traditional dry mixing method. Irrespective of the method used, the use of near-spherical beads with a fairly narrow size range results in unif...

in this paper, the magnetohydrodynamic (mhd) boundary layer flow over a nonlinear porous stretching sheet is investigated by employing the homotopy perturbation transform method (hptm) and the pade´ approximation. the numerical solution of the governing non-linear problem is developed. comparison of the present solution is made with the existing solution and excellent agreement is noted. graphi...

We present an efficient and accurate characteristic method for the solution of the unsteady-state advection-diffusion transport equations, which arise in the mathematical models for flow and transport processes in porous media. The advantages of this method include symmetrizing the governing transport equation, treating boundary conditions naturally in the formulation, and conserving mass. More...