1. Non-Monotonic Relaxation of Density Fluctuation in GlassesSabyasachi Sen, University of California at Davis,DMR 0603933 A fundamental understanding of glass relaxation behavior is vital to the glass and polymer science communities. While prior work has focused on relaxation of first-order thermodynamic properties such as enthalpy and density, little is known about the relaxation behavior of fluctuations in these properties that are ubiquitous in glasses and liquids. Sen and colleagues have used high-temperature small-angle x-ray scattering measurements to detect and quantify the relaxation behavior of density fluctuation in glasses for the first time. Their results directly demonstrate that while density relaxes monotonically, the fluctuations relax non-monotonically. These results provide direct evidence for the presence of dynamical heterogeneities and their close association with density fluctuations. Our results also indicate that density fluctuations, and hence light scattering, can be minimized through design of thermal history. These findings have far-reaching implications in the areas of fiber optics and optical display technology for designing glasses with small density fluctuations. Physical Review Letters, 102, 155506 (2009). Isothermal relaxation of density fluctuation of a display glass at 868 K after prior equilibration at 953 K. Red triangles and blue circles represent results from two separate runs.

2. Non-Monotonic Relaxation of Density Fluctuation in GlassesSabyasachi Sen, University of California at Davis,DMR 0603933 • Graduate students Ms. Sezen Soyer-Uzun and Ms. Erica Gjersing have presented their research in the form of oral presentation at the 8th Pacific Rim Conference on Ceramic and Glass Technology, held in Vancouver, Canada in June, 2009. Ms. Soyer-Uzun will be finishing her Ph.D. in Fall, 2009 and will be joining Lawrence Berkeley National Laboratory as a postdoctoral fellow. • Students participating in the “Glass: Science and technology” course offered in the Spring of 2009 were taken to a field trip to the Pilkington Glass plant in Lathrop, California. This trip provided an important exposure to the details of industrial scale glass manufacturing processes. • Photo above shows the attendees in the 2009 IUPAC International Conference on High Temperature Materials Chemistry (HTMC-13, held at UC Davis in September, 2009) that was co-organized (with Profs. Alex Navrotsky and Charles Lesher) where an entire session was devoted to high-temperature glass-forming liquids. This session brought scientists from different disciplines (materials science, geology, chemistry and physics) together in a dialogue.