Retention, Detention and Overland Flow for Pollutant Removal from Highway Stormwater Runoff, Volume II: Design Guidelines

DTFH61-85-C-00117This volume is the second in a two-volume report which developed design guidelines and specifications for measures to reduce or eliminate the impacts of highway runoff on surface waters. This report provides design guidelines and specifications for three types of management measures for the removal of pollutants from highway stormwater runoff. The three general types of management measures, determined through previous FHWA studies to be effective in treating highway runoff, are: retention systems (basins, trenches, and wells), detention basins (wet detention basins, dry extended detention basins, and wetlands), and overland flow (grassed channels and filter strips). These guidelines have been developed based on the experience of the project team, review of available literature, and bench-scale and field testing

Resonant and off-resonant transients in electromagnetically induced transparency: Turn-on and turn-off dynamics

Published versio

Horizontal Branch Stars: The Interplay between Observations and Theory, and Insights into the Formation of the Galaxy

We review HB stars in a broad astrophysical context, including both variable and non-variable stars. A reassessment of the Oosterhoff dichotomy is presented, which provides unprecedented detail regarding its origin and systematics. We show that the Oosterhoff dichotomy and the distribution of globular clusters (GCs) in the HB morphology-metallicity plane both exclude, with high statistical significance, the possibility that the Galactic halo may have formed from the accretion of dwarf galaxies resembling present-day Milky Way satellites such as Fornax, Sagittarius, and the LMC. A rediscussion of the second-parameter problem is presented. A technique is proposed to estimate the HB types of extragalactic GCs on the basis of integrated far-UV photometry. The relationship between the absolute V magnitude of the HB at the RR Lyrae level and metallicity, as obtained on the basis of trigonometric parallax measurements for the star RR Lyrae, is also revisited, giving a distance modulus to the LMC of (m-M)_0 = 18.44+/-0.11. RR Lyrae period change rates are studied. Finally, the conductive opacities used in evolutionary calculations of low-mass stars are investigated. [ABRIDGED]Comment: 56 pages, 22 figures. Invited review, to appear in Astrophysics and Space Scienc

Retention, Detention, and Overland Flow for Pollutant Removal from Highway Stormwater Runoff, Volume I: Research Report

DTFH61-85-C-00117This volume is the first in a two-volume report which developed design guidelines and specifications for measures to reduce or eliminate the impacts of highway runoff on surface waters. This volume documents the research performed under this project. It presents the findings of literature reviews, laboratory bench-scale testing, and actual field monitoring of pollution control measures (grassed channels and wet detention basins)