Air permeability is used to characterize textile fabrics with respect their usability as a garment or filter, airbag parachute. It depends on the fabric’s porosity, air voids in fabric, yarn specifications, thickness and other parameters, making it hard calculate reliably from parameters. At same time, measuring requires relatively expensive complex equipment that cannot simply be built by ever...

Several existing equations for solving the non-linear soil-hydraulic properties are introduced and validated to field and laboratory measured data. Models for non-linear hydraulic properties of unsaturated porous media arise from statistical and mathematical fit through the measured data and they can be expressed in forms of unsaturated permeability versus either pressure head or volumetric moi...

Cuticular water permeabilities of adaxial and abaxial leaf surfaces and their dependence on relative air humidity (RH) applied in long-term and short-term regimes have been analysed for Hedera helix, native in a temperate climate, and Zamioculcas zamiifolia, native in subtropical regions. The water permeability of cuticular membranes (CM) isolated from the adaxial (astomatous) and abaxial (stom...

This study aimed to experimentally acquire evolution profiles between depth, bulk density, Free Air Space (FAS), air permeability and thermal conductivity in initial composting materials. The impact of two different moisture content, two particle size and two types of bulking agent on these four parameters was also evaluated. Bulk density and thermal conductivity both increased with depth while...

This paper presents a novel approach to assessing textile porosity by the application of the image analysis techniques. The images of different types of sample fabrics, taken through a microscope when the fabric is placed over a constant light source, transfer the problem into the image analysis domain. Indeed, porosity can thus be expressed in terms of a brightness percentage index calculated ...

This paper presents preliminary experimental results on the measurement of the air permeability coefficient in a concrete sample that has been subjected to constant pressure differences of 5 and 10 Pa (3.45 x 1 0 ' ~ 6.90 x 1u2 psi). This experimental model simulates indoor radon gas entry by advection. A reliable air permeability system was designed to perform laboratory measurements on concre...