Strengthening Out-of-School Time Nonprofits: The Role of Foundations in Building Organizational Capacity

Placing nonprofits in the larger context of city, state, and national policy, explores the capacity-building support nonprofits running afterschool and summer programs need to provide high-impact networks of learning and developmental opportunities

Damped bounces of an isolated perfect quantum gas

The issue of the thermalization of an isolated quantum system is addressed by considering a perfect gas confined by gravity and initially trapped above a certain height. As we are interested in the behavior of truly isolated systems, we assume the gas is in a pure state of macroscopically well-defined energy. We show that, in general, for single-particle distributions, such a state is strictly equivalent to the microcanonical mixed state at the same energy. We derive an expression for the time-dependent gas density which depends on the initial gas state only via a few thermodynamic parameters. Though we consider non-interacting particles, the density relaxes into an asymptotic profile, but which is not the thermal equilibrium one determined by the gas energy and particle number

Continuous-Time Random Walks at All Times

Continuous-time random walks (CTRW) play important role in understanding of a wide range of phenomena. However, most theoretical studies of these models concentrate only on stationary-state dynamics. We present a new theoretical approach, based on generalized master equations picture, that allowed us to obtain explicit expressions for Laplace transforms for all dynamic quantities for different CTRW models. This theoretical method leads to the effective description of CTRW at all times. Specific calculations are performed for homogeneous, periodic models and for CTRW with irreversible detachments. The approach to stationary states for CTRW is analyzed. Our results are also used to analyze generalized fluctuations theorem