A modified polarographic method with inert gas for determination of the oxygen permeability in polymers immersed in liquids is described. Owing to the stream of an inert gas towards polymer from the cathode side, lateral oxygen diffusion (edge effects) is minimized. Unlike the standard Fatt method, the method with inert gas is suitable also for thick samples and, therefore, for high-permeable m...

Solubility and permeability of gases in glassy polymers have been considered with the aim of illustrating the applicability of thermodynamically-based models for their description and prediction. The solubility isotherms are described by using the nonequilibrium lattice fluid (NELF) (model, already known to be appropriate for nonequilibrium glassy polymers, while the permeability isotherms are ...

Ultra-high performance concrete (UHPC) is a developing concrete and today is increasing to interest using it in structures due to its advantages such as high-compressive strength, modulus of elasticity, highly durability and low-permeability. Therefore, it is necessary to provide models for prediction of nonlinear behavior of this material. This study is aimed to investigate the tension-stiffen...

The No. 21 coal seam in the Zhengzhou mining area is a soft, three-layer, low-permeability prone to outbursts. three-layer structure includes and roof floor layers, which exhibit high gas contents poor permeability. dynamic hazards caused by outbursts are very serious. A new permeability-increasing fracturing technique that combines hydraulic perforation was developed specifically for geologic ...