Systematics of Fission-Product Yields (open access)

Systematics of Fission-Product Yields

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Date: May 5, 2002
Creator: A.C.Wahl
Object Type: Report
System: The UNT Digital Library
Diffractive optical elements based on Fourier optical techniques: A new class of optics for extreme ultraviolet and soft x-ray wavelengths (open access)

Diffractive optical elements based on Fourier optical techniques: A new class of optics for extreme ultraviolet and soft x-ray wavelengths

None
Date: May 5, 2002
Creator: Chang, Chang; Naulleau, Patrick; Anderson, Erik; Rosfjord, Kristine & Attwood, David
Object Type: Article
System: The UNT Digital Library
Background Radioactivity in River and Reservoir Sediments near Los Alamos, New Mexico (open access)

Background Radioactivity in River and Reservoir Sediments near Los Alamos, New Mexico

As part of its continuing Environmental Surveillance Program, regional river and lake-bottom sediments have been collected annually by Los Alamos National Laboratory (the Laboratory) since 1974 and 1979, respectively. These background samples are collected from three drainage basins at ten different river stations and five reservoirs located throughout northern New Mexico and southern Colorado. Radiochemical analyses for these sediments include tritium, strontium-90, cesium-137, total uranium, plutonium-238, plutonium-239,-240, americium-241, gross alpha, gross beta, and gross gamma radioactivity. Detection-limit radioactivity originates as worldwide fallout from aboveground nuclear weapons testing and satellite reentry into Earth's atmosphere. Spatial and temporal variations in individual analyte levels originate from atmospheric point-source introductions and natural rate differences in airborne deposition and soil erosion. Background radioactivity values on sediments reflect this variability, and grouped river and reservoir sediment samples show a range of statistical distributions that appear to be analyte dependent. Traditionally, both river and reservoir analyte data were blended together to establish background levels. In this report, however, we group background sediment data according to two criteria. These include sediment source (either river or reservoir sediments) and station location relative to the Laboratory (either upstream or downstream). These grouped data are statistically evaluated through 1997, and background …
Date: May 5, 2002
Creator: McLin, Stephen G. & Lyons, Dale W.
Object Type: Report
System: The UNT Digital Library
Final report of research supported by DOE Grant No. DE-FG02-96ER14635: Photochemical studies of two component systems within the restricted spaces of zeolites. (open access)

Final report of research supported by DOE Grant No. DE-FG02-96ER14635: Photochemical studies of two component systems within the restricted spaces of zeolites.

Most chemistry in nature occurs within a closed and confined space. In contrast to this time-evolved [m?] organic chemists have focused their interests in developing reaction methods in solution. The price for this is paid in terms of non-selectivity in product formation, expensive reagents, and enormous wastes. Eventually 'man-developed' solution methods to make molecules have to be replaced by more selective, more environmentally friendly, and less expensive strategies. One approach in this direction would be to use controlled environments. The project focused towards developing energy efficient methods to prepare energy rich molecules that were useful to the public. In this context synthetic zeolites, the counterpart of naturally occurring minerals, were explored as the reaction media.
Date: May 5, 2002
Creator: Ramamurthy, V.
Object Type: Report
System: The UNT Digital Library