For over a decade, research from the gas permeation community has observed faster physical aging rates with decreasing thickness of free-standing films, termed "accelerated aging". These deviations in the aging rate from bulk behavior occur at film thicknesses of several micrometers, the largest "confinement" length scale ever reported. Here we systematically address various possible causes of this phenomenon from differences in molecular structure, quench depth below T g , experimental technique, sample preparation, and stresses on the film. We demonstrate that the physical aging of the material is strongly dependent on conditions during the formation of the glassy state. Although supported films do not display any film thickness dependence to their aging rate at this large length scale, films quenched in a free-standing state exhibit a strong thickness dependence. We suggest differing quench conditions may impose unintended stresses trapping the glassy films into different states (potential energy minima), dictating the subsequent physical aging rate.

The recently proposed reduction method for diluted spin glasses is investigated in depth. In particular, the Edwards-Anderson model with ±J and Gaussian bond disorder on hyper-cubic lattices in d = 2, 3, and 4 is studied for a range of bond dilutions. The results demonstrate the effectiveness of using bond dilution to elucidate low-temperature properties of Ising spin glasses, and provide a starting point to enhance the methods used in reduction. Based on that, a new greedy heuristic call "Dominant Bond Reduction" is introduced and explored.

Numerous studies have demonstrated the potential for particles in fluids to exhibit complicated dynamical behavior. In this work, we study a horizontal rotating drum filled with pure glycerol and three large, heavy spheres. The rotation of the drum causes the spheres to cascade and tumble and thus interact with each other. We find several different behaviors of the spheres depending on the drum rotation rate. Simpler states include the spheres remaining well separated, or states where two or all three of the spheres come together and cascade together. We also see two more complex states, where two or three of the spheres move erratically. The main signature of this erratic motion is that pairs of spheres intermittently approach each other ͑sometimes colliding͒ and then separate; the time between collisions is variable even for a fixed rotation rate. We characterize these disordered states and find a complex phase space with a rich set of behaviors. This experiment serves as a simple model system to demonstrate complex behavior in simple fluid dynamical systems.