NASA Scientific and Technical Aerospace Reports

20060002352 Brookhaven National Lab., Upton, NY, USA
Stopping and Baryon Transport in Heavy Ion Reactions
Videbaek, F.; Feb. 2005; 14 pp.; In English
Report No.(s): DE2005-15016378; BNL-74683; No Copyright; Avail.: Department of Energy Information Bridge
In this report I will give an experimental overview on nuclear stopping in hadron collisions, and relate observations to
understanding of baryon transport. Baryon number transport is not only evidenced via net-proton distributions but also by the
enhancement of strange baryons near mid-rapidity. Although the focus is on high-energy data obtained from pp and heavy ions
from RHIC, relevant data from SPS and ISR will be considered. A discussion how the available data at higher energy relates
and gives information on baryon junction, quark-diquark breaking will be made.
NTIS
Baryons; Heavy Ions
20060002360 Virginia Transportation Research Council, Charlottesville, VA USA
Comparison of Alternative Devices to Determine Aggregate Shape
McGhee, K. K.; Deeds, T. M.; Rorrer, T. M.; Nov. 2005; 32 pp.; In English
Report No.(s): PB2006-101930; VTRC-06-R10; No Copyright; Avail.: National Technical Information Service (NTIS)
This study compared devices (with corresponding procedures) that may be used to classify flat and elongated (F&E)
particle content for coarse aggregate sources. The comparison involved the traditional (and manual) proportional caliper and
two digital calipers. The material used to conduct these comparisons was from aggregate sources used to produce stone-matrix
asphalt during the 2003 and 2004 construction seasons in Virginia. Replicate tests were conducted for each source and each
device. The same material was tested by multiple technicians from the Virginia Transportation Research Council’s asphalt
laboratory and the Virginia Department of Transportation’s central materials laboratory. The central conclusions were: (1) the
vertically operated digital caliper is a suitable alternative to the traditional manual proportional caliper; (2) the ROCLOG
software facilitates data reduction; and (3) it is important to consider the full gradation analysis when characterizing F&E
content of any aggregate source. This research also documented an estimated time-savings of 45 minutes per aggregate source
when performing F&E testing with the vertically operated digital caliper. Given VDOT’s standard requirements for aggregate
testing, this translates into an annual time-savings of at least 30 hours per laboratory. With an advertised cost of less than $300
per device, the benefit to cost ratio for the vertically operated digital caliper is better than 4 to 1, and the investment is easily
justifiable.
NTIS
Aggregates; Asphalt; Shapes
20060002390 Brookhaven National Lab., Upton, NY USA
Performance Calculation on Orbit feedback for NSLS-II
Yu, L. H.; January 2005; 10 pp.; In English
Report No.(s): DE2005-15016376; BNL-74676-2005; No Copyright; Avail.: National Technical Information Service (NTIS)
We discuss the preliminary calculation on the performance of closed orbit feedback system for NSLSII, its relation to the
requirement on BPM, floor and girder stability, power supply stability etc.
NTIS
Feedback; Light Sources; Synchrotrons
20060002393 National Renewable Energy Lab., Golden, CO USA
AFM-Based Microelectrical Characterization of Grain Boundaries in Cu(In,Ga) Se2 Thin Films
Jiang, C. S.; Noufi, R.; Ramanathan, K.; Feb. 2005; 12 pp.; In English
Report No.(s): DE2005-15016399; NREL/CP-520-37338; No Copyright; Avail.: Department of Energy Information Bridge
We report on a direct measurement of two-dimensional potential distribution on the surface of Cu(In,Ga)Se2 thin films
using a nanoscale electrical characterization of scanning Kelvin probe microscopy both in air and in ultra-high vacuum. The
potential measurement reveals a higher surface potential or a smaller work function on grain boundaries (GBs) of the film than
on the grain surfaces. This demonstrates the existence of a local built-in potential on GBs, and the GB is positively charged.
The role of the built-in potential in device performance was further examined and found to be positive, by tuning Ga content
or bandgap of the film. With increasing Ga content, the potential drops sharply in a Ga range of 28%-38%. Comparing the
change in the built-in potential to the theoretical and experimental photoconversion efficiencies, we conclude that the potential
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