MGA is a gamma-ray spectrum analysis program for determining relative plutonium isotopic abundances. The isotopic composition of a plutonium sample is needed to calculate {sup 240}Pu{sub eff} that is used to interpret passive neutron coincidence measurements in units of absolute plutonium mass. MGA can determine plutonium isotopic abundances with accuracies better than 1% using a high-resolution, low-energy, planar germanium detector and measurement times ten minutes or less. MGA can include analysis of a second spectrum of the high-energy (300--600 keV) plutonium gamma rays that significantly improves the determination of {sup 240}P{sub eff} in high-burnup plutonium. For the high-energy gamma-ray measurements we have devised a new hardware configuration, so that both the low- and high-energy gamma-ray detectors are mounted in a single cryostat thereby reducing weight and volume of the detector systems. We describe the detector configuration and our experience with it using a combined neutron-gamma measurement system and the two-detector version of MGA. We discuss the sources of uncertainty in the determination of {sup 240}Pu{sub eff} and propose a new correlation for the determination of {sup 242}Pu.

Self-lubricating composites consist of at least one structural (matrix) phase and at least one phase to provide lubrication. Modeling the behavior of such composites involves ascertaining the frictional contributions of each constituent phase under varying conditions of lubricating films coverage. The ORNL friction microprobe (FMP), a specialized microcontact tribometer, was used to investigate the frictional behavior of both matrix and lubricant phases to support the development of self-lubricating, surfaces. Polished CVD-silicon carbide deposits and silicon wafers were used as substrates. The wafers were intended to simulate the thin silica films present on SiC surfaces at elevated temperature. Molybdenum disulfide, in both sputtered and burnished forms, was used as the model lubricant. The effects of CVD-SiC substrate surface roughness and method of lubricant film deposition on the substrate were studied for single passes of a spherical silicon nitride slider (NBD 200 material). In contrast to the smooth sliding exhibit by burnished, films, sputtered MoS{sub 2} surfaces exhibited marked stick-slip behavior, indicating that the frictional behavior of solid lubricating coatings can be quite erratic on a microscale, especially when asperity contacts are elastically compliant.

Newsletter of the Texas Department of Health discussing the news, activities, and events of the organization and other information related to health in Texas.

Weekly newsletter discussing natural resources, parks, hunting and fishing, and other information related to the outdoors in Texas.

President Clinton proposed to Prime Minister Miyazawa the idea of a framework for U.S.-Japanese negotiations during their April 13, 1993 meeting in Washington. The two leaders agreed to instruct subordinates to prepare details of such a framework in time for presentation in July in Tokyo when the President would meet with the Prime Minister and the other G-7 leaders at the annual economic summit.

Progress is briefly presented on the research pertaining to insulated building blocks. Areas covered include development of a stuffing machine, fabrication, sound tests, and earthquake test design.

The Short-Term Energy Outlook Annual Supplement (supplement) is published once a year as a complement to the Short-Term Energy Outlook (Outlook), Quarterly Projections. The purpose of the Supplement is to review the accuracy of the forecasts published in the Outlook, make comparisons with other independent energy forecasts, and examine current energy topics that affect the forecasts.