EFFECT OF PRETREATMENT ON PT-CO/C CATHODE CATALYSTS FOR THE OXYGEN-REDUCTION REACTION (open access)

EFFECT OF PRETREATMENT ON PT-CO/C CATHODE CATALYSTS FOR THE OXYGEN-REDUCTION REACTION

In order to reduce the precious metal loading without sacrificing activity and stability, a new method for the preparation of bimetallic catalysts is proposed. Currently, Pt-alloy particles, with 2 to 3 nm in diameter, are loaded on high surface area carbon supports. Of the Pt loaded, only the surface atoms interact with the reactants. In order to increase the Pt utilization per metal particle the new process for catalyst preparation will incorporate a non-noble transition metal core coated with a skin layer of Pt deposited on high surface area carbon. The effect of reducing agent strength during synthesis was also explored. It was determined that the Co addition has a higher impact on catalyst when used with NaBH4 as reducing agent as compared to NaCOOH.
Date: May 13, 2009
Creator: Fox, E.
Object Type: Article
System: The UNT Digital Library
K-311-1/K-310-3 Purge Cascade Process Description, Oak Ridge Environmental Management Accelerated Cleanup Project, Oak Ridge, Tennessee (open access)

K-311-1/K-310-3 Purge Cascade Process Description, Oak Ridge Environmental Management Accelerated Cleanup Project, Oak Ridge, Tennessee

K-311-1 was constructed along with the rest of the K-25 Building in the 1943-1945 timeframe. K-311-1 was equipped with Size 3 converters and Size 38 Allis Chalmers{trademark} single-stage centrifugal compressors driven by 3600 rpm electric motors, and the unit operated as the 'bottom' unit flow-wise in K-25. The depleted flow from the bottom stage in K-311-1 passed through booster compressors and flowed to the K-601 Building where the depleted or 'tails' material was removed. In 1948, after the K-27 Building was completed, the decision was made to operate K-27 and K-25 in series rather than operate the two buildings as separate entities. To facilitate this operation, concrete bases were poured and two sets of booster compressors were installed in the extreme West end of the K-311-1 cell floor. These compressors were enclosed in heated housings and consisted of Size 38 compressors. One pair was to boost the 'B' flow between K-25 and K-27, and one pair was to boost the 'A' flow between the buildings. Each station operated with one compressor on-stream and the other in standby. (Reference 9) Each station also was equipped with a Size 2 after-cooler located in the discharge stream downstream of the junction of the …
Date: May 13, 2009
Creator: J.E., Shoemaker
Object Type: Report
System: The UNT Digital Library
Section on prospects for dark matter detection of the white paper on the status and future of ground-based TeV gamma-ray astronomy. (open access)

Section on prospects for dark matter detection of the white paper on the status and future of ground-based TeV gamma-ray astronomy.

This is a report on the findings of the dark matter science working group for the white paper on the status and future of TeV gamma-ray astronomy. The white paper was commissioned by the American Physical Society, and the full white paper can be found on astro-ph (arXiv:0810.0444). This detailed section discusses the prospects for dark matter detection with future gamma-ray experiments, and the complementarity of gamma-ray measurements with other indirect, direct or accelerator-based searches. We conclude that any comprehensive search for dark matter should include gamma-ray observations, both to identify the dark matter particle (through the characteristics of the gamma-ray spectrum) and to measure the distribution of dark matter in galactic halos.
Date: May 13, 2009
Creator: Byrum, K.; Horan, D.; Tait, T.; Wanger, R.; Zaharijas, G.; Buckley , J. et al.
Object Type: Report
System: The UNT Digital Library