CRATES: An All-Sky Survey of Flat-Spectrum Radio Sources (open access)

CRATES: An All-Sky Survey of Flat-Spectrum Radio Sources

We have assembled an 8.4 GHz survey of bright, flat-spectrum ({alpha} > -0.5) radio sources with nearly uniform extragalactic (|b| > 10{sup o}) coverage for sources brighter than S{sub 4.8 GHz} = 65 mJy. The catalog is assembled from existing observations (especially CLASS and the Wright et al. PMN-CA survey), augmented by reprocessing of archival VLA and ATCA data and by new observations to fill in coverage gaps. We refer to this program as CRATES, the Combined Radio All-sky Targeted Eight GHz Survey. The resulting catalog provides precise positions, sub-arcsecond structures, and spectral indices for some 11,000 sources. We describe the morphology and spectral index distribution of the sample and comment on the survey's power to select several classes of interesting sources, especially high energy blazars. Comparison of CRATES with other high-frequency surveys also provides unique opportunities for identification of high-power radio sources.
Date: February 20, 2007
Creator: Healey, Stephen E.; Romani, Roger W.; Taylor, Gregory B.; Sadler, Elaine M.; Ricci, Roberto; Murphy, Tara et al.
Object Type: Article
System: The UNT Digital Library
POLYCHLORINATED BIPHENYL COMPLIANCE ISSUES IN THE 21ST CENTURY: POORLY RECOGNIZED AND POTENTIALLY DEVASTATING-8162 (open access)

POLYCHLORINATED BIPHENYL COMPLIANCE ISSUES IN THE 21ST CENTURY: POORLY RECOGNIZED AND POTENTIALLY DEVASTATING-8162

Thirty-one years have passed since the United States Congress passed the Toxic Substances Control Act (TSCA) [1]. The 1976 law essentially eliminated future production of polychlorinated biphenyls (PCBs) within the United States and greatly limited the use of previously manufactured PCBs and PCB products. The ultimate objective of the law was the complete elimination of these chemicals due to concerns about their potentially toxic effects on health and the environment. PCBs were manufactured in the United States between 1929 and 1977. They were highly valued for their fire and heat-resistance properties and for their chemical stability. As a result, PCBs were used in a variety of thermally and/or chemically stressful applications. They did not conduct electricity and therefore were particularly well-suited for use as insulating fluids in high-voltage electric equipment. PCBs were also used in various other applications, such as in hydraulic and heat transfer fluids. Strict controls on the use and disposal of PCBs were imposed by the TSCA implementing regulations at 40 CFR 761 [2]. As a result, most heavy users of PCB products worked hard to curtail their PCB use. Many organizations that once used substantial amounts of PCBs, subsequently declared themselves ''PCB free''. Unfortunately, in many …
Date: November 20, 2007
Creator: Lowry, N
Object Type: Article
System: The UNT Digital Library
Extracellular Proteins Limit the Dispersal of Biogenic Nanoparticles (open access)

Extracellular Proteins Limit the Dispersal of Biogenic Nanoparticles

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Date: February 20, 2007
Creator: Moreau, J W; Weber, P K; Martin, M C; Gilbert, B; Hutcheon, I D & Banfield, J F
Object Type: Article
System: The UNT Digital Library
Directing Matter and Energy: Five Challenges for Science and the Imagination (open access)

Directing Matter and Energy: Five Challenges for Science and the Imagination

The twin aspects of energy and control (or direction) are the underlying concepts. Matter and energy are closely linked, and their understanding and control will have overwhelming importance for our civilization, our planet, our science, and our technology. This importance ranges even beyond the large portfolio of BES, both because these truly significant Grand Challenges confront many other realms of science and because even partial solutions to these challenges will enrich scientists’ collective imagination and ability to solve problems with new ideas and new methods.
Date: December 20, 2007
Creator: Hemminger, J.; Fleming, G. & Ratner, M.
Object Type: Report
System: The UNT Digital Library
LDRD Annual Report FY2006 (open access)

LDRD Annual Report FY2006

The Laboratory Directed Research and Development (LDRD) Program, authorized by Congress in 1991 and administered by the Laboratory Science and Technology Office, is our primary means for pursuing innovative, long-term, high-risk, and potentially high-payoff research that supports the missions of the Laboratory, the Department of Energy, and National Nuclear Security Administration in national security, energy security, environmental management, bioscience and technology to improve human health, and breakthroughs in fundamental science and technology. The accomplishments described in this Annual Report demonstrate the strong alignment of the LDRD portfolio with these missions and contribute to the Laboratory's success in meeting its goals. The LDRD budget of $92 million for FY2006 sponsored 188 projects. These projects were selected through an extensive peer-review process to ensure the highest scientific quality and mission relevance. Each year, the number of deserving proposals far exceeds the funding available, making the selection a tough one indeed. Our ongoing investments in LDRD have reaped long-term rewards for the Laboratory and the nation. Many Laboratory programs trace their roots to research thrusts that began several years ago under LDRD sponsorship. In addition, many LDRD projects contribute to more than one mission area, leveraging the Laboratory's multidisciplinary team approach to science …
Date: March 20, 2007
Creator: Sketchley, J. A.; Kotta, P.; De Yoreo, J.; Jackson, K. & Van Bibber, K.
Object Type: Report
System: The UNT Digital Library