AbstracG-The hydrodynamic boundary condition at the interface between a porous and a plain medium is examined by direct simulation of the two-dimensional flow field near the interface of a porous medium made of cylinders. The existing slip boundary condition, which contains a slip coefficient a, and the noslip boundary condition, which contains an effective viscosity p’, are examined. The depen...

Mass transport in porous materials is universal in nature, and its worth attracts great attention in many engineering applications. Plant leaves, which work as natural hydraulic pumps for water uptake, have evolved to have the morphological structure for fast water transport to compensate large water loss by leaf transpiration. In this study, we tried to deduce the advantageous structural featu...

Hierarchical anatase TiO(2) porous nanopillars with high crystallinity and stability were fabricated by the following four steps: (i) synthesis of a titanium glycolate nanopillar precursor; (ii) transformation into stable nanopillars consisting of amorphous TiO(2) primary nanoparticles at low temperature; (iii) treatment with ethylenediamine aqueous solution to protect the nanopillar structure,...

To evaluate the variability of multiphase flow properties of porous media at the pore scale, it is necessary to acquire a number of representative samples of the void-solid structure. While modern x-ray computer tomography has made it possible to extract three-dimensional images of the pore space, assessment of the variability in the inherent material properties is often experimentally not feas...

Advanced additive manufacturing techniques such as electron beam melting (EBM), can produce highly porous structures that resemble the mechanical properties and structure of native bone. However, for orthopaedic applications, such as joint prostheses or bone substitution, the surface must also be bio-functionalized to promote bone growth. In the current work, EBM porous Ti6Al4V alloy was expose...

Water is an integral part of the structure in biological porous materials such as wood and starch. A problem often encountered in the preparation of samples for, e.g., electron microscopy is that removal of water leads to a decreasing distance between supermolecular structural elements and a distortion of the structure. It is, therefore, of interest to find methods to investigate these material...

A novel and aqueous gel-casting process has been successfully developed to fabricate porous MgAl₂O₄ ceramics by using hydratable alumina and MgO powders as raw materials and deionized water as hydration agent. The effects of different amounts of deionized water on the hydration properties, apparent porosity, bulk density, microstructure, pore size distribution and compressive strength of the sa...

A new chemical sensor based on attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy has been fabricated by coating an ATR crystal with a hydrophobic mesoporous silica film. The highly porous coating can extract hydrophobic analyres, such as benzene, from aqueous solutions and concentrate them inside the film. The enrichment of the analytes inside the film provides the...

In this work, sawdust, a biomass waste, is converted into a magnetic porous carbonaceous (MPC) solid acid catalyst by an integrated fast pyrolysis-sulfonation process. The resultant magnetic solid acid has a porous structure with high surface area of 296.4 m(2) g(-1), which can be attributed to the catalytic effect of Fe. The catalytic activity and recyclability of the solid acid catalyst are e...

In this study, a composite system made of multiple porous block structure used for flow and heat transfer control will be analyzed. The primary objective of this study is to analyze the changes in the flow pattern and heat transfer characteristics due to the existence of the multiple porous block structure. A general flow model that accounts for the effects of the impermeable boundary and inert...