New energy storage concept uses tapes

Energy storage system uses movable permeable tapes with cathode and electrolyte material that is drawn across an anode to produce electric power. The system features long shelf life, high efficiency, and flexible operation

SU(m|n) supersymmetric Calogero-Sutherland model confined in harmonic potential

In this work, we study a continuous quantum system of a mixture of bosons and fermions with the supersymmetry SU(m|n). The particles are confined in a harmonic well and interact with each other through the 1/r2 interaction. The ground state wavefunction is constructed explicitly for the most general SU(m|n) case, with the ground state energy given explicitly. The full energy spectrum of excitations in the SU(m|n) model is also equal spaced. In the limiting case where there are no bosons in the system, our results reduce to those obtained previously.Comment: 9 pages, preprint of ETH-Lausanne (August 1996

Ground States and Flux Configurations of the Two-dimensional Falicov-Kimball Model

The Falicov-Kimball model is a lattice model of itinerant spinless fermions ("electrons") interacting by an on-site potential with classical particles ("ions"). We continue the investigations of the crystalline ground states that appear for various filling of electrons and ions, for large coupling. We investigate the model for square as well as triangular lattices. New ground states are found and the effects of a magnetic flux on the structure of the phase diagram is studied. The flux phase problem where one has to find the optimal flux configurations and the nuclei configurations is also solved in some cases. Finaly we consider a model where the fermions are replaced by hard-core bosons. This model also has crystalline ground states. Therefore their existence does not require the Pauli principle, but only the on-site hard-core constraint for the itinerant particles.Comment: 42 pages, uuencoded postscript file. Missing pages adde

Public Health Insurance and Private Savings

Recent theoretical work suggests that means and asset-tested social insurance programs can explain the low savings of lower income households in the United States. We assess the validity of this hypothesis by investigating the effect of Medicaid, the health insurance program for low-income women and children, on savings behavior. We do so using data on asset holdings from the Survey of Income and Program Participation, and on consumption from the Consumer Expenditure Survey, matched to information on the eligibility of each household for Medicaid. Exogenous variation in Medicaid eligibility is provided by the dramatic expansion of this program over the 1984–1993 period. We document that Medicaid eligibility has a sizeable and significant negative effect on wealth holdings; we estimate that in 1993 the Medicaid program lowered wealth holdings by 17.7 percent among the eligible population. We confirm this finding by showing a strong positive association between Medicaid eligibility and consumption expenditures; in 1993, the program raised consumption expenditures among eligibles by 5.2 percent. We also exploit the fact that asset testing was phased out by the Medicaid program over this period to document that these Medicaid effects are stronger in the presence of an asset test, confirming the importance of asset testing for household savings decisions.