An integrated process for the production of methyl acetate and methanol by the carbonylating dimethyl ether with synthesis gas, recovering methyl and unreacted synthesis gas and wherein the recovered synthesis gas is utilized as the sole fresh synthesis gas for methanol synthesis. Here \u03c9 is the angular velocity of the disk and f is a resonant frequency of a head assembly containing the head. A process for producing diffusion membranes comprises dispersing uncalcined PTFE, calcined PTFE and a conductive substance in a dispersion medium, removing the dispersion medium, adding a liquid lubricant followed by kneading, compressing the resultant kneaded product to expand the same into a membrane, and removing the liquid lubricant. Each space has one or more openings, in either the inner or outer layers, and preferably at the shoulders or sides of the torso, or at the pocket areas of pants.