Sound propagation in water-saturated granular sediments is known to depend on the sediment porosity, but few data in the literature address both the frequency and porosity dependency. To begin to address this deficiency, a fluidized bed technique was used to control the porosity of an artificial sediment composed of glass spheres of 265 μm diameter. Time-of-flight measurements and the Fourier p...

The substitution of matrix permeability for fracture permeability to simplify the simulation of complex fracture systems requires a radically different treatment of transport in the matrix. The spatial distribution of pressure is reasonably well described by inclusion of only the major fractures. Transport of tracer and heat, however, depends on a detailed knowledge of fluid velocities. These v...

electrospinning is a method of nanofiber filter media production. by this method, it is possibleto produce media with nanofiber in the range of nanometer to micrometer. nanofibrous media provide a large specific surface area in a finite volume thus they are suitable for filtration applications. in this study, nanofiber non-woven membranes production of nylon-6 by electrospinning method is inves...

It is widely recognized that groundwater flow and solute transport in natural media are largely controlled by heterogeneities. In the last three decades, many studies have examined the effects of heterogeneous hydraulic conductivity fields on flow and transport processes, but there has been much less attention to the influence of heterogeneous porosity fields. In this study, we use porosity and...

where u = − K∇p is the Darcy phase velocity, proportional to the gradient of the phase pressure p . The other coe cients in the model are: the porosity, q a source term, the phase mobility and K the permeability of the porous medium. The di erence between the phase pressures is the capillary pressure pc =pn − pw and we also assume that the sum of the phase saturations is equal to one. The bound...

A computer simulation model is used to study the density profile and flow of a miscible gaseous fluid mixture consisting of differing constituent masses (mA = mB/3) through an open matrix. The density profile is found to decay with the height ∝ exp(−mA(B)h), consistent with the barometric height law. The flux density shows a power-law increase ∝ (pc − p) μ with μ ≃ 2.3 at the porosity 1− p abov...

3.2. Effects on soil health, quality and fertility 3.2.1. Soil organic matter 3.2.2. Biological properties 3.2.3. Chemical properties 3.2.3.1. pH 3.2.3.2. N 3.2.3.3. P 3.2.3.4. K 3.2.3.5. Other elements 3.2.3.6. Electrical conductivity 3.2.3.7 Cation Exchange Capacity 3.2.4. Physical properties 3.2.4.1. Water holding capacity and porosity 3.2.4.2. Bulk density/Penetration resistance 3.2.4.3. Ag...

STATEMENT OF PROBLEM The occurrence porosity in polymethyl methacrylate, the most commonly used denture base material is a problem. The occurrence of oral candidiasis and other infections has also been reported in denture users. PURPOSE The aim of this study was to evaluate the effect of addition of an antimicrobial agent, silver zeolite on the porosity of denture base resin, which will be an...

A .—Although the ultimate factors that infl uence the duration of avian incubation periods are well known, we know much less about the proximate mechanisms by which birds adjust incubation period in response to selection. We tested the hypothesis that an adjustment in eggshell porosity is one such proximate mechanism (i.e., that avian species with higher ratios of incubation period to egg size ...

Measurements of porosity and pore size distribution provide important data on the physical properties of soils. This paper presents a digital image method for the analysis of soil pores. In the analysis of soil thin sections, the image threshold separating pore space from the surrounding solid, as well as the capillary pore size threshold separating air pores and capillary pores, was obtained b...