$(2$pts$)$ Describe what happens to the gas phase $($in terms of pressure, temperature and composition$)$ and the adsorbed phase $($in terms of composition$)$ during column purging in a PSA or VSA cycle.

$(2$pts$)$ Describe what happens to the gas phase $($in terms of pressure, temperature and composition$)$ and the adsorbed phase $($in terms of composition$)$ during column blowdown in a TSA cycle.