66,863 research outputs found
2003 Pollutant Loads Kings River Near Berryville, Arkansas
An automatic sampler and a USGS gauging station were established in 1998 and water quality sampling was begun in 1999 on the Kings River near Berryville, Arkansas. Continuous stage and discharge measurements and frequent water quality sampling have been used to determine pollutant concentrations and loads in the river. This report presents the results from the sampling and analysis for January 1, 2003 to December 31, 2003
On the Evolution, Numbers, and Characteristics of Close-Binary Supersoft Sources
The ability to perform detailed evolutionary calculations is essential to the
development of a well-defined and testable binary model. Unfortunately,
traditional evolutionary calculations cannot be used to follow a significant
fraction of possible close-binary supersoft sources (CBSSs). It is therefore
important to examine the input physics carefully, to be sure that all relevant
and potentially important physical processes are included. In this paper we
continue a line of research begun last year, and explore the role that winds
are expected to play in the evolution of CBSSs. We find that at least a subset
of the systems that seemed to be candidates for common envelope evolution may
survive, if radiation emitted by white dwarf drives winds from the system. We
study the effects of winds on the binary evolution of CBSSs, and compute the
number and characteristics of CBSSs expected to be presently active in galaxies
such as our own or M31.Comment: 13 pages; figures included in 0.33 M postscript file; in Supersoft
X-ray Sources, ed. J. Greiner (Springer-Verlag: Berlin) (1996
Compositions of near-Earth asteroids
The goal is to determine whether any of the near-earth asteroids contain water-bearing phyllosilicate (clay) minerals. If these minerals are present, they would provide a readily available source of water for propellant generation and use in life support systems. Telescopic detection of water on the near-earth asteroids is complicated because thermal emission from the asteroid itself masks the diagnostic absorption features for objects this close to the sun. Sophisticated thermal models are necessary to determine whether the absorption features are present. This year, development of these models was continued and more telescopic data to test the models was obtained
On Measurement of Helicity Parameters in Top Quark Decay
To enable an evaluation of future measurements of the helicity parameters for
" t --> W b " decay in regard to " T_FS violation", this paper considers the
effects of an additional pure-imaginary coupling, (i g/2 Lambda) or (i g),
associated with a specific, single additional Lorentz structure, i = S, P, S +
P, ... Sizable " T_FS violation" signatures can occur for low-effective mass
scales (< 320 GeV), but in most cases can be more simply excluded by 10%
precision measurement of the probabilities P(W_L) and P(b_L). Signatures for
excluding the presence of " T_FS violation" associated with the two dynamical
phase-type ambiguities are investigated.Comment: 15 pages, 1 table, 7 figures, no macro
Plastic flow around rigid spherical inclusions
The extent of plastic flow in a spherical solid (assumed to be homogeneous and elastically and plastically isotropic), surrounding a concentric rigid sphere was calculated as a function of applied external pressure. The applied pressure necessary to cause plastic deformation throughout the solid was obtained
Use of steel and tantalum apparatus for molten Cd-Mg-Zn alloys
Steel and tantalum apparatus contains various ternary alloys of cadmium, zinc, and magnesium used in pyrochemical processes for the recovery of uranium-base reactor fuels. These materials exhibit good corrosion resistance at the high temperatures necessary for fuel separation in liquid metal-molten salt solvents
Study made of resistance of stainless steels to zinc-vapor corrosion
Study of the corrosion resistance of several stainless steels to zinc vapor revealed that some stainless steels could be employed for use in zinc processing equipment housings or vapor lines
Stress anisotropy and concentration effects in high pressure measurements
Sodium chloride is used as an internal pressure standard in high pressure research. Possible corrections are discussed which are needed in the calibration of this standard due to the independent effects of stress anisotropy and stress concentration in pressure vessels. The first is due to the lack of a truly hydrostatic state of stress in solid state pressure vessels. The second is due to the difference in the compressibilities between the pressure transmitting substances (sodium chloride) and a stiffer test specimen. These two corrections are then combined and a total correction, as a function of measured pressure, is discussed for two systems presently in use. The predicted value of the combined effect is about 5-10% of the pressure at 30 GPa
Development of deployable structures for large space platform systems, volume 2
Ground test article design, deployable volumes concept development, habitat and hangar conceptual designs, and deployable volumes analyses are addressed
Development of deployable structures for large space platform systems. Volume 1: Executive summary
Candidate deployable linear platform system concepts suitable for development to technology readiness by 1986 are reviewed. The systems concepts were based on trades of alternate deployable/retractable structure concepts, integration of utilities, and interface approaches for docking and assembly of payloads and subsystems. The deployable volume studies involved generation of concepts for deployable volumes which could be used as unpressurized or pressurized hangars, habitats and interconnecting tunnels. Concept generation emphasized using flexible materials and deployable truss structure technology
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