CLOSE-OUT REPORT FOR HYS ELECTROLYZER COMPONENT DEVELOPMENT WORK AT SAVANNAH RIVER NATIONAL LABORATORY (open access)

CLOSE-OUT REPORT FOR HYS ELECTROLYZER COMPONENT DEVELOPMENT WORK AT SAVANNAH RIVER NATIONAL LABORATORY

The chemical stability, sulfur dioxide transport, ionic conductivity, and electrolyzer performance have been measured for several commercially available and experimental proton exchange membranes (PEMs) for use in a sulfur dioxide depolarized electrolyzer (SDE). The SDE's function is to produce hydrogen by using the Hybrid Sulfur (HyS) Process, a sulfur based electrochemical/thermochemical hybrid cycle. Membrane stability was evaluated using a screening process where each candidate PEM was heated at 80 C in 63.5 wt. % H{sub 2}SO{sub 4} for 24 hours. Following acid exposure, chemical stability for each membrane was evaluated by FTIR using the ATR sampling technique. Membrane SO{sub 2} transport was evaluated using a two-chamber permeation cell. SO{sub 2} was introduced into one chamber whereupon SO{sub 2} transported across the membrane into the other chamber and oxidized to H{sub 2}SO{sub 4} at an anode positioned immediately adjacent to the membrane. The resulting current was used to determine the SO{sub 2} flux and SO{sub 2} transport. Additionally, membrane electrode assemblies (MEAs) were prepared from candidate membranes to evaluate ionic conductivity and selectivity (ionic conductivity vs. SO{sub 2} transport) which can serve as a tool for selecting membranes. MEAs were also performance tested in a HyS electrolyzer measuring current density versus …
Date: January 20, 2010
Creator: Colon-Mercado, H.; Elvington, M. & Hobbs, D.
Object Type: Report
System: The UNT Digital Library
Effective thermal boundary resistance from thermal decoupling of magnons and phonons in SrRuO3 thin films (open access)

Effective thermal boundary resistance from thermal decoupling of magnons and phonons in SrRuO3 thin films

We use the time-resolved magneto-optical Kerr effect (TRMOKE) to measure the local temperature and heat flow dynamics in ferromagnetic SrRuO3 thin films. After heating by a pump pulse, the film temperature decays exponentially, indicating that the heat flow out of the film is limited by the film/substrate interface. We show that this behavior is consistent with an effective boundary resistance resulting from disequilibrium between the spin and phonon temperatures in the film.
Date: January 20, 2010
Creator: Langner, M. C.; Kantner, C. L. S.; Chu, Y. H.; Martin, L. M.; Yu, P.; Ramesh, R. et al.
Object Type: Article
System: The UNT Digital Library
Impact of intrinsic localized modes of atomic motion on materials properties (open access)

Impact of intrinsic localized modes of atomic motion on materials properties

Recent neutron and x-ray scattering measurements show intrinsic localized modes (ILMs) in metallic uranium and ionic sodium iodide. Here, the role ILMs play in the behavior of these materials is examined. With the thermal activation of ILMs, thermal expansion is enhanced, made more anisotropic, and, at a microscopic level, becomes inhomogeneous. Interstitial diffusion, ionic conductivity, the annealing rate of radiation damage, and void growth are all influenced by ILMs. The lattice thermal conductivity is suppressed above the ILM activation temperature while no impact is observed in the electrical conductivity. This complement of transport properties suggests that ILMs could improve thermoelectric performance. Ramifications also include thermal ratcheting, a transition from brittle to ductile fracture, and possibly a phase transformation in uranium.
Date: January 20, 2010
Creator: Manley, M E
Object Type: Article
System: The UNT Digital Library
Shear Strength Correlations for Kaolin/Water Slurries: A Comparison of Recent Measurements with Historical Data (open access)

Shear Strength Correlations for Kaolin/Water Slurries: A Comparison of Recent Measurements with Historical Data

This report documents testing funded by CH2M Hill Plateau Remediation and performed by Pacific Northwest National Laboratory (PNNL) in collaboration with Fauske and Associates, LLC (FAI) to determine the behavior of vessel spanning bubbles. The shear strengths of four samples of kaolin/water mixtures obtained by PNNL from FAI were measured and are reported here. The measured shear strengths of these samples were then used to determine how the Rassat correlation fit these new measurements or if a new correlation was needed. These results were then compared with previously reported data.
Date: January 20, 2010
Creator: Burns, Carolyn A.; Gauglitz, Phillip A. & Russell, Renee L.
Object Type: Report
System: The UNT Digital Library