49 research outputs found

    Fax/Modem Capabilities; Technology Alert, August 1994

    Get PDF
    https://egrove.olemiss.edu/aicpa_news/2852/thumbnail.jp

    Comparing Futures for the Sacramento-San Joaquin Delta

    Get PDF
    Analyzes expected changes to the hub of California's water system and presents a comparative assessment of four water management strategies for environmental sustainability and water supply reliability. Discusses policy and regulatory implications

    Redshifts and Velocity Dispersions of Galaxy Clusters in the Horologium-Reticulum Supercluster

    Get PDF
    We present 118 new optical redshifts for galaxies in 12 clusters in the Horologium-Reticulum supercluster (HRS) of galaxies. For 76 galaxies, the data were obtained with the Dual Beam Spectrograph on the 2.3m telescope of the Australian National University at Siding Spring Observatory. After combining 42 previously unpublished redshifts with our new sample, we determine mean redshifts and velocity dispersions for 13 clusters, in which previous observational data were sparse. In six of the 13 clusters, the newly determined mean redshifts differ by more than 750 km/s from the published values. In the case of three clusters, A3047, A3109, and A3120, the redshift data indicate the presence of multiple components along the line of sight. The new cluster redshifts, when combined with other reliable mean redshifts for clusters in the HRS, are found to be distinctly bi-modal. Furthermore, the two redshift components are consistent with the bi-modal redshift distribution found for the inter-cluster galaxies in the HRS by Fleenor et al. (2005).Comment: 13 pages, 3 figures, Accepted to A

    Large-Scale Velocity Structures in the Horologium-Reticulum Supercluster

    Get PDF
    We present 547 optical redshifts obtained for galaxies in the region of the Horologium-Reticulum Supercluster (HRS) using the 6dF multi-fiber spectrograph on the UK Schmidt Telescope at the Anglo Australian Observatory. The HRS covers an area of more than 12deg x 12deg on the sky centered at approximately RA = 03h19m, DEC = -50deg 02amin. Our 6dF observations concentrate upon the inter-cluster regions of the HRS, from which we describe four primary results. First, the HRS spans at least the redshift range from 17,000 to 22,500 km s^-1. Second, the overdensity of galaxies in the inter-cluster regions of the HRS in this redshift range is estimated to be 2.4, or del rho/ rho ~ 1.4. Third, we find a systematic trend of increasing redshift along a Southeast-Northwest (SE-NW) spatial axis in the HRS, in that the mean redshift of HRS members increases by more than 1500 km s^-1 from SE to NW over a 12 deg region. Fourth, the HRS is bi-modal in redshift with a separation of ~ 2500 km s^-1 (35 Mpc) between the higher and lower redshift peaks. This fact is particularly evident if the above spatial-redshift trend is fitted and removed. In short, the HRS appears to consist of two components in redshift space, each one exhibiting a similar systematic spatial-redshift trend along a SE-NW axis. Lastly, we compare these results from the HRS with the Shapley supercluster and find similar properties and large-scale features.Comment: 20 pages, 9 figures, accepted to A

    Simplified 1-D Hydrodynamic and Salinity Transport Modeling of the Sacramento–San Joaquin Delta: Sea Level Rise and Water Diversion Effects

    No full text
    Long-term hydrodynamic and salinity transport modeling of the Sacramento–San Joaquin Delta is needed to evaluate the future Delta in terms of the California co-equal goals of ecosystem health and reliable water supply. While 2-D and 3-D hydrodynamic and water quality models are by definition better suited to modeling a complex network of tidally influenced flows under future conditions, a 1-D model is more computationally efficient in narrowing the large variety of multiple-year simulations required into a more manageable task. Still, a 1-D model of sea level rise in an estuary must account for the three-dimensional effects where increased depths will affect density driven (baroclinic) circulation and tidal dispersion of salt. In this paper, we use a simplified Delta network model with a tidally averaged computational approach to quickly perform multi-year simulations for sea level rise. The 1-D model uses tidal dispersion coefficients developed from 3-D hydrodynamic models. The resulting model is capable of performing very fast simulations over a wide range of conditions, providing guidance on what should be explored in depth with more detailed, but slower models. Comparisons of unimpaired Delta inflow with the historical case show that the south Delta and San Joaquin River would be much fresher without exports, while the Sacramento River would be fresher in spring and more saline in the fall. Sea level rise will increase salinity throughout the Delta over time. With peripheral conveyance of export, water salinity will intrude upstream in the Sacramento River, be slightly lower up the San Joaquin River and increase in the south Delta. With sea level rise, peripheral conveyance will have similar trends to changes to the historical case, but export salinity will be improved by the peripheral conveyance component. A larger peripheral conveyance can benefit both the ecosystem and exports if managed properly. </p
    corecore