National FCEV Learning Demonstration: Spring 2011 All Composite Data Products With Updates Through March 29, 2011

This presentation from the U.S. Department of Energy's National Renewable Energy Laboratory includes all the composite data products produced to date (with updates through March 29, 2011) as part of the National Fuel Cell Electric Vehicle (FCEV) Learning Demonstration

Wetting to Non-wetting Transition in Sodium-Coated C_60

Based on ab initi and density-functional theory calculations, an empirical potential is proposed to model the interaction between a fullerene molecule and many sodium atoms. This model predicts homogeneous coverage of C_60 below 8 Na atoms, and a progressive droplet formation above this size. The effects of ionization, temperature, and external electric field indicate that the various, and apparently contradictory, experimental results can indeed be put into agreement.Comment: 4 pages, 4 postscript figure

Viscoelastic response of sonic band-gap materials

A brief report is presented on the effect of viscoelastic losses in a high density contrast sonic band-gap material of close-packed rubber spheres in air. The scattering properties of such a material are computed with an on-shell multiple scattering method, properties which are compared with the lossless case. The existence of an appreciable omnidirectional gap in the transmission spectrum, when losses are present, is also reported.Comment: 5 pages, 4 figures, submitted to PR

Low-temperature structural model of hcp solid C70_{70}

We report intermolecular potential-energy calculations for solid C_${70}$ and determine the optimum static orientations of the molecules at low temperature; we find them to be consistent with the monoclinic structural model proposed by us in an earlier report [Solid State Commun. {\bf 105), 247 (1998)]. This model indicates that the C_5 axis of the molecule is tilted by an angle $\approx$18^o from the monoclinic b axis in contrast with the molecular orientation proposed by Verheijen {\it et al.} [J. Chem. Phys. {\bf 166}, 287 (1992)] where the C_5 axis is parallel to the monoclinic b axis. In this calculation we have incorporated the effective bond charge Coulomb potential together with the Lennard-Jones potential between the molecule at the origin of the monoclinic unit cell and its six nearest neighbours, three above and three below. The minimum energy configuration for the molecular orientations turns out to be at $\theta$=18^o, $\phi$=8^o, and $\psi$=5^o, where $\theta$, $\phi$, and $\psi$ define the molecular orientations.Comment: ReVTeX (4 pages) + 2 PostScript figure

ARRA Material Handling Equipment Composite Data Products: Data through Quarter 2 of 2013

This report includes 47 composite data products (CDPs) produced for American Recovery and Reinvestment Act (ARRA) fuel cell material handling equipment, with data through the second quarter of 2013

Learning Demonstration Progress Report -- Spring 2008

This report documents key results from DOE's Controlled Hydrogen Fleet and Infrastructure Validation and Demonstration Project based on data through December 2007

Analysis of Ultracapacitor-VRLA Energy Storage Systems for Mild Hybrids

Presents an analysis of VRLA + ultracapacitor use as energy storage systems in mild hybrid vehicles

Controlled Hydrogen Fleet and Infrastructure Demonstration and Validation Project; Spring 2008 Composite Data Products, Final Version: February 29, 2008

Graphs of composite data products produced by DOE's Controlled Hydrogen Fleet and Infrastructure Demonstration and Validation project through February 2008

Thermal compression of two-dimensional atomic hydrogen to quantum degeneracy

We describe experiments where 2D atomic hydrogen gas is compressed thermally at a small "cold spot" on the surface of superfluid helium and detected directly with electron-spin resonance. We reach surface densities up to 5e12 1/cm^2 at temperatures of approximately 100 mK corresponding to the maximum 2D phase-space density of about 1.5. By independent measurements of the surface density and its decay rate we make the first direct determination of the three-body recombination rate constant and get the value of 2e-25 cm^4/s for its upper bound, which is an order of magnitude smaller than previously reported experimental results.Comment: 4 pages, 4 postscript figures, bibliography (.bbl) file, submitted to PR

Controlled Hydrogen Fleet and Infrastructure Analysis

This presentation by Keith Wipke at the 2008 DOE Hydrogen Program Annual Merit Review Meeting provides information about NREL's Controlled Hydrogen Fleet and Infrastructure Analysis Project