Initial formation of the U.S. Geological Survey hydroclimatic data network [abstract]

EXTRACT (SEE PDF FOR FULL ABSTRACT): The U.S. Geological Survey is working to define a hydroclimatic data network. The Geological Survey collects stream discharge data at more than 7000 sites throughout the United States. Many of these stations are operated to supply information about specific activities such as flood control, irrigation projects, or hydropower generation. As a beginning, the Geological Survey will attempt to identify stations that represent natural streamflow. Several lists of stations representing "natural" streamflow have been complied in the past. While there is some overlap among these lists, a consistent compilation is preferred. The present effort is to produce one list identifying those stations having periods of record which would be suitable for mesoscale climatic analyses

Molecular modeling of microporous structures of carbide-derived carbon-based supercapacitors

Microporous carbide-derived carbons are an important structural class for various technological applications. We present two possible strategies based on molecular dynamics simulations for modeling microporous amorphous carbon. In addition, we have investigated the influence of the precursor structure and simulation parameters on the porosity of the final model structure. We observed a minor influence of the precursor structure on the porosity and found that the structural properties such as pore size and hybridization in the modeled carbon structures agree well with experimental findings. Moreover, CO2 adsorption isotherms have been simulated using Monte Carlo simulations for comparsion with experimental data. In this context, we have also considered partially oxidized carbon structures for which an increased uptake of CO2 was observed

Distinguishing spins in decay chains with photons at the Large Hadron Collider

Several models for physics beyond the Standard Model predict new particles with a decay signature including hard photons and missing energy. Two well-motivated examples are supersymmetry with gauge-mediated breaking (GMSB) and the standard model with two universal extra dimensions. Both models lead to decay chains with similar collider signatures, including hard photon emission. The main discriminating feature are the spins of the new particles. In this paper we discuss how information about the spins of the particles can be extracted from lepton-photon or quark-photon invariant mass distributions at the Large Hadron Collider. The characteristic shapes of the distributions are derived analytically and then studied in a realistic Monte-Carlo simulation. We find that for a typical GMSB mass spectrum with particle masses below 1 TeV, already 10 fb$^{-1}$ integrated luminosity at 14 TeV center-of-mass energy are sufficient to discriminate the two models with high significance.Comment: 26 pages, 7 postscript figures, published versio