For the case of flame thickness being of the order of the pore linear dimension, the flame structure and speed in adiabatic, premixed methane-air combustion in porous media are examined. The local, volume-averaged conservation equations that assume a local thermal equilibrium between the solid and the gas phases (i.e. the single-medium treatment) or allow for a thermal nonequilibrium (i.e. the ...

Mesoporous calcium-silicon xerogels with a pore size of 15 nm (MCS-15) and pore volume of 1.43 cm(3)/g were synthesized by using 1,3,5-mesitylene (TMB) as the pore-expanding agent. The MCS-15 exhibited good degradability with the weight loss of 50 wt% after soaking in Tris-HCl solution for 56 days, which was higher than the 30 wt% loss shown by mesoporous calcium-silicon xerogels with a pore si...

In this work, we report a new hybrid nanomaterial based on the immobilization of 4-formyl benzo-9-crown-3 ether (FB9C3) onto the mesopores of MCM-41. First, the mesoporous molecular sieve MCM-41 was covalently grafted with 3-aminopropyl triethoxysilane to give aminopropyl modified MCM-41 (AmpMCM-41). Reaction of this material with FB9C3 afforded the B9C3-AmpMCM-41 hybrid nanomaterial. The prepa...

the n-(2-benzoyl-phenyl) oxalyl derivatives are important models for studying of three-centered intramolecular hydrogen bonding in organic molecules. the quantum theoretical calculations for two crystal structures of n-(2-benzoyl-phenyl) oxalyl (compounds i and ii) were performed by density functional theory (b3lyp method and 6-311+g* basis set). from the optimized structures, geometric paramet...

A nanopore is the ultimate analytical tool. It can be used to detect DNA, RNA, oligonucleotides, and proteins with submolecular sensitivity. This extreme sensitivity is derived from the electric signal associated with the occlusion that develops during the translocation of the analyte across a membrane through a pore immersed in electrolyte. A larger occluded volume results in an improvement in...

Abstract The pore-structure characteristics of hybrid basalt–polypropylene fibre-reinforced concrete were investigated by using mercury intrusion porosimetry. applicability various fractal models in characterising the HBPRC pore structure was compared. results show that types and content fibres different influences on cumulative volume basalt-polypropylene concrete. Compared with pore-volume so...

This paper describes the use of thermodynamic modeling to predict reaction products and properties cementitious pastes containing fly ash. A pore partitioning model is used estimate gel capillary volumes. The paste performance predicted in terms its porosity, compressive strength, formation factor, deicing salt damage susceptibility. proposed quantify refinement that occurs when ash used. Compa...