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We have studied HST/FOS far ultraviolet spectra of AGNs. We observed that Galactic Halo absorption in the 3C 273 sight line has large C IV and Si IV equivalent widths compared to the other Galactic halo sight lines in our sample. The 3C 273 sight line is near the edge of Radio Loop I, which is also one of the brightest soft X-ray sources in the sky. An attempt has been made to study the effect of this loop on interstellar absorption. We have observed, with IUE, an A star (HD 108228) which is near to the 3C 273 sight line and believed to be at a distance beyond the loop. We used stellar modeling to deconvolve stellar from interstellar lines. The results of our analysis are presented. We also have observations of PKS 1351+640 which has a high Si IV equivalent width and whose sight line crosses a high velocity 21 cm cloud which abuts on soft X-ray emitting gas. It is possible that surface effects in regions of soft X-ray and H I emission produce the strong high ion absorption though processes such as turbulent mixing layers, shocks, or thermal conduction. The Galactic halo absorption equivalent widths in the spectra of these and 4 other AGNs in the ions C II, C IV, Si II, Si IV, Al II, and Al III are presented.
