A hydrodynamic permeability of membranes built up by porous cylindrical or spherical particles with impermeable core is investigated. Different versions of a cell method are used to calculate the hydrodynamic permeability of the membranes. Four known boundary conditions, namely, Happel's, Kuwabara's, Kvashnin's and Cunningham/Mehta-Morse's, are considered on the outer surface of the cell. Compa...

BACKGROUND One of the most important challenges about the Membrane Bio Reactors is membrane fouling. Fouling has been at the centre of a globe debate for more recent years. It leads to high operational and maintenance costs such as membrane damage and replacement of membrane. Membrane fouling is attributed to the physicochemical interactions between the bio fluid and membrane. In order to decre...

in this work, sio2 –zro2 mixed oxides was prepared by the polymeric sol–gel route. the characterization of pore structure, which determines the permeation process of membrane, is of great importance. so far, most investigations have focused on such pore structure as specific surface area and pore size distribution, but the surface fractal, the important parameter reflecting the roughness of por...

to investigate the saturation induced collapse deformation behavior of rockfill material, a set of large-scale triaxial tests were conducted in saturated and dry-saturated conditions. specimens were tested under various confining pressures. for dry-saturated tests, specimens were sheared in various stress levels. results of all dry saturated tests indicate a sudden reduction in the specimen vol...

There are few physical objects as beautiful and fascinating as soap bubbles. They exhibit a perfection of geometrical form and an appealing simplicity. Soap bubbles are characterized by the structure of their thin liquid shell of low surface tension. It is well known that the dynamics of the surface of soap bubbles are the resultant of both 1) liquid film thinning under the influence of gravity...

The rapid growth in natural gas consumption has increased the need for gas storage, in particular in the form of injection into depleted reservoirs. Also, CO2 sequestration into the depleted reservoirs has attracted a large attention recently. However, it is important to ensure that the injection pressure is maintained below a certain limit to avoid unsealing the cap rock or reactivation of any...

We present detailed results for the motion of a finite sized gas bubble in a blood vessel. The bubble (dispersed phase) size is taken to be such as to nearly occlude the vessel. The bulk medium is treated as a shear thinning Casson fluid and contains a soluble surfactant that adsorbs and desorbs from the interface. Three different vessel sizes, corresponding to a small artery, a large arteriole...

sandwich sheet rolling process is investigated using an analytical method (slab method) and a numerical method (finite element method). the horizontal stress distribution in the layers, the rolling pressure along the contact interface and the neutral point between the roll and the sheet are investigated. then the affects of the parameters such as the friction between the sheet and the roll, she...