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
Object Type: Article
System: The UNT Digital Library
High Temperature, Low Relative Humidity, Polymer-type Membranes Based on Disulfonated Poly(arylene ether) Block and Random Copolymers Optionally Incorporating Protonic Conducting Layered Water insoluble Zirconium Fillers (open access)

High Temperature, Low Relative Humidity, Polymer-type Membranes Based on Disulfonated Poly(arylene ether) Block and Random Copolymers Optionally Incorporating Protonic Conducting Layered Water insoluble Zirconium Fillers

Our research group has been engaged in the past few years in the synthesis of biphenol based partially disulfonated poly(arylene ether sulfone) random copolymers as potential PEMs. This series of polymers are named as BPSH-xx, where BP stands for biphenol, S stands for sulfonated, H stands for acidified and xx represents the degree of disulfonation. All of these sulfonated copolymers phase separate to form nano scale hydrophilic and hydrophobic morphological domains. The hydrophilic phase containing the sulfonic acid moieties causes the copolymer to absorb water. Water confined in hydrophilic pores in concert with the sulfonic acid groups serve the critical function of proton (ion) conduction and water transport in these systems. Both Nafion and BPSH show high proton conductivity at fully hydrated conditions. However proton transport is especially limited at low hydration level for the BPSH random copolymer. It has been observed that the diffusion coefficients of both water and protons change with the water content of the pore. This change in proton and water transport mechanisms with hydration level has been attributed to the solvation of the acid groups and the amount of bound and bulk-like water within a pore. At low hydration levels most of the water is …
Date: June 3, 2010
Creator: McGrath, James E. & Baird, Donald G.
Object Type: Report
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.
Object Type: Article
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.
Object Type: Article
System: The UNT Digital Library
GROUT TEMPERATURE MEASUREMENTS IN 105-R DISASSEMBLY BASIN D AND E CANAL (open access)

GROUT TEMPERATURE MEASUREMENTS IN 105-R DISASSEMBLY BASIN D AND E CANAL

The 105-R Reactor Disassembly Basin Grout Placement Strategy Report (SRNL-TR-2009-00157) identifies various portions of the facility that will undergo an in-situ decommissioning process. The estimated residual radioactive contamination in the 105-R facility is shown in Figure 1. Cementitious grout formulations developed by SRNL are being used to immobilize and isolate the radioactive contamination in existing below grade portions of the 105-R building as shown by the gray-hatched area in Figure 2. A Zero Bleed flowable fill was formulated for both dry placement and for underwater placement. The first major area in the 105-R Disassembly Basin to undergo the grouting process was the D&E Canal and an underlying void space known as the Chase. Grout temperature data was needed to ensure that the grout mix design was on the correct grout curing trajectory to meet the material compressive strength requirement of 50 pounds per square inch. Initial grout temperature measurements were needed to confirm and optimize grout mix design fresh property characteristics; i.e. material strength, and set time. Grout curing temperature is an integrating fresh property characteristic that is used to estimate cementitious material strength in accordance with the Standard Practice for Estimating Concrete Strength by the Maturity Method, ASTM C …
Date: June 3, 2010
Creator: Fogle, R.; Collins, M. & Guerrero, H.
Object Type: Report
System: The UNT Digital Library
Evaluation of Best Available Control Technology for Toxics (Tbact) Double Shell Tank Farms Primary Ventilation System Supporting Waste Transfer Operations (open access)

Evaluation of Best Available Control Technology for Toxics (Tbact) Double Shell Tank Farms Primary Ventilation System Supporting Waste Transfer Operations

This report is an evaluation of Best Available Control Technology for Toxics (tBACT) for installation and operation of the Hanford double shell (DST) tank primary ventilation systems. The DST primary ventilation systems are being modified to support Hanford's waste retrieval, mixing, and delivery of single shell tank (SST) and DST waste throught the DST storage system to the Waste Treatment and Immobilization Plant (WTP).
Date: June 3, 2010
Creator: Kelly, S. E.; Haass, C. C.; Kovach, J. L. & Turner, D. A.
Object Type: Report
System: The UNT Digital Library
DESCRIPTION OF THE LAWRENCE LIVERMORE NATIONAL LABORATORY SYNTHETIC GAMMA RAY SOURCE (open access)

DESCRIPTION OF THE LAWRENCE LIVERMORE NATIONAL LABORATORY SYNTHETIC GAMMA RAY SOURCE

None
Date: June 3, 2010
Creator: Luke, S J
Object Type: Report
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

None
Date: June 3, 2010
Creator: Maiti, A.; Bourcier, W. L. & Aines, R. D.
Object Type: Article
System: The UNT Digital Library