0 Assigned ID: 1022 ----- Attempting Submission 1 (Fri Apr 07 22:44:34 GMT 2017) ----- While it is well recognized that both the Galactic interstellar extinction curves and the gas-phase abundances of C, O and other metal elements exhibit considerable variations from one sightline to another, as yet most of the dust extinction modeling efforts have been directed to the Galactic average extinction curve which is obtained by averaging over many clouds of different gas and dust properties. Therefore, any details concerning the relationship between the dust properties and the interstellar environments are lost. By utilizing the wealth of extinction and abundance data obtained by IUE, HST, and FUSE, we propose to explore the dust properties of over 100 individual sight lines by simultaneously both fitting the observed extinction curve from the near-infrared to the far-ultraviolet and conforming to the observed abundance constraints. This will allow us to gain insight into the physical nature of interstellar grains and how they are related to the physical and chemical conditions of their environments. The results of this research will greatly benefit the analysis and understanding of previously acquired data from GHRS and STIS and future data obtained with STIS. Galaxies and the IGM 0 Regular false false true SUPPORTED