captured by the zeolite, while the other cylinder is vented off to ambient atmospheric pressure allowing the captured nitrogen to dissipate. Such units typically have cycles of around 20 seconds and allow for a continuous supply of oxygen at a flow rate of up to approximately five liters per minute (LPM) at concentrations anywhere from 50 to 95%. A similar prior art process is known as Vacuum Swing Adsorption (VSA), which uses a single low pressure blower and a valve which reverses the flow through the blower so that the regeneration phase occurs under a vacuum. A still further alternative prior art approach to oxygen concentration employs technology known as Advanced Technology Fractionator (ATF). A rotary distribution valve built into the ATF directs the flow of compressed airEquity Partners for $300 million – which severed all editorial connections between the magazine and website, including the end of critic Matt Roush's presence on TVGuide.com. The editorial content of the magazine was launched on a new site, TVGuideMagazine.com, which did not feature TV Guides listings in any form. TVGuideMagazine.com was later shut down on June 1, 2010; TV Guide magazine and TVGuide.com then entered into a deal to restore content from the magazine to the latter website, which Lionsgate Entertainment had bought along with the TV Guide Network in January 2009.

In January 2009, the magazine cut several networks from its grid listings – including MTV and DIY Network – citing "space concerns"; however, two cuts, those of The CW and TV Guide Network, were seen as suspicious