Sythesis of metal sulfide nanomaerials via thermal decomposition of single-source percursors (open access)

Sythesis of metal sulfide nanomaerials via thermal decomposition of single-source percursors

In this report, we present a synthetic method for the formation of cuprous sulfide (Cu2S) and lead sulfide (PbS) nanomaterials directly on substrates from the thermolysis of single-source precursors. We find that the final morphology and arrangement of the nanomaterials may be controlled through the concentration of the dissolved precursors and choice of solvent. One-dimensional (1-D) morphologies may also be grown onto substrates with the addition of a metal catalyst layer through solution-liquid-solid (SLS) growth. These synthetic techniques may be expanded to other metal sulfide materials.
Date: June 3, 2010
Creator: Jen-La Plante, Ilan; Zeid, Tahani W.; Yang, Peidong & Mokari, Taleb
System: The UNT Digital Library
Application of Absorption Spectroscopy to Actinide Process Analysis and Monitoring (open access)

Application of Absorption Spectroscopy to Actinide Process Analysis and Monitoring

The characteristic strong colors of aqueous actinide solutions form the basis of analytical techniques for actinides based on absorption spectroscopy. Colorimetric measurements of samples from processing activities have been used for at least half a century. This seemingly mature technology has been recently revitalized by developments in chemometric data analysis. Where reliable measurements could formerly only be obtained under well-defined conditions, modern methods are robust with respect to variations in acidity, concentration of complexants and spectral interferents, and temperature. This paper describes two examples of the use of process absorption spectroscopy for Pu analysis at the Savannah River Site, in Aiken, SC. In one example, custom optical filters allow accurate colorimetric measurements of Pu in a stream with rapid nitric acid variation. The second example demonstrates simultaneous measurement of Pu and U by chemometric treatment of absorption spectra. The paper concludes with a description of the use of these analyzers to supplement existing technologies in nuclear materials monitoring in processing, reprocessing, and storage facilities.
Date: June 3, 2010
Creator: Lascola, R. & Sharma, V.
System: The UNT Digital Library
Using a Risk-Based Methodology for the Transfer of Radioactive Material Within the Savannah River Site Boundary (open access)

Using a Risk-Based Methodology for the Transfer of Radioactive Material Within the Savannah River Site Boundary

Shipment of radioactive materials (RAM) is discussed in the Code of Federal Regulations in parts of both 49 CFR and 10 CFR. The regulations provide the requirements and rules necessary for the safe shipment of RAM across public highways, railways, waterways, and through the air. These shipments are sometimes referred to as in-commerce shipments. Shipments of RAM entirely within the boundaries of Department of Energy sites, such as the Savannah River Site (SRS), can be made using methodology allowing provisions to maintain equivalent safety while deviating from the regulations for in-commerce shipments. These onsite shipments are known as transfers at the SRS. These transfers must follow the requirements approved in a site-specific Transportation Safety Document (TSD). The TSD defines how the site will transfer materials so that they have equivalence to the regulations. These equivalences are documented in an Onsite Safety Assessment (OSA). The OSA can show how a particular packaging used onsite is equivalent to that which would be used for an in-commerce shipment. This is known as a deterministic approach. However, when a deterministic approach is not viable, the TSD allows for a risk-based OSA to be written. These risk-based assessments show that if a packaging does not …
Date: June 3, 2010
Creator: Loftin, B.; Watkins, R. & Loibl, M.
System: The UNT Digital Library
CO2 capture in primary and tertiary amines - insights from atomistic modeling (open access)

CO2 capture in primary and tertiary amines - insights from atomistic modeling

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Date: June 3, 2010
Creator: Maiti, A.; Bourcier, W. L. & Aines, R. D.
System: The UNT Digital Library