Boildown Study on Supernatant Liquid Retrieved from AP-107 in May 2010 (open access)

Boildown Study on Supernatant Liquid Retrieved from AP-107 in May 2010

A boildown study was completed on a composite prepared from supernatant liquid grab samples retrieved from tank 241-AP-107 in May of 2010. The composite was a clear, yellow liquid containing no visible solids at hot cell ambient temperatures (25-27 °C). The density of the test composite was 1.216 g/mL at 26.8 °C. The boiling temperature curves generated at three reduced pressures—40-, 60-, and 80 Torr—displayed steadily increasing boiling temperatures with increasing volume reduction with no significant discontinuities. Only minimal foaming was observed after the volume reduction proceeded beyond 50 %WVR (percent waste volume reduction). The bulk densities (D{sub Bulk}{sup 18 °C}) and quantities of settled and centrifuged solids present were measured on samples of the boildown concentrates that were kept at 18 °C for 7-8 days. Estimated values of the bulk densities of the concentrates at 60-Torr boiling temperatures (D{sub Bulk}{sup 60 Torr}) were also calculated. Solids were observed in all boildown concentrates at process temperatures, at hot cell ambient temperatures (25-27 °C), and at 18 °C. The quantity of solids found in the cooled concentrates increased slowly through 50.2 %WVR. The quantity of solids found in concentrates after 54.0 %WVR was noticeably greater. Beyond 54.0 %WVR, the quantity of …
Date: February 12, 2013
Creator: Callaway, W. S. & Page, J. S.
Object Type: Report
System: The UNT Digital Library
Comprehensive Algorithmic Resilience for Numeric Applications (open access)

Comprehensive Algorithmic Resilience for Numeric Applications

None
Date: February 12, 2013
Creator: Chen, S; Bronevetsky, G; Casas-Guix, M & Peng, L
Object Type: Article
System: The UNT Digital Library
Hybrid MPI: Efficient Message Passing for Shared and Distributed Memory (open access)

Hybrid MPI: Efficient Message Passing for Shared and Distributed Memory

None
Date: February 12, 2013
Creator: Friedley, A; Bronevetsky, G; Hoefler, T & Lumsdaine, A
Object Type: Article
System: The UNT Digital Library
FLAME-SAMPLING PHOTOIONIZATION MASS SPECTROSCOPY - FINAL TECHNICAL REPORT (open access)

FLAME-SAMPLING PHOTOIONIZATION MASS SPECTROSCOPY - FINAL TECHNICAL REPORT

Research focused on detailed studies of the complex combustion chemistry of oxygenated, bio-derived fuels. In particular, studies were done of the flame chemistry of simple methyl and ethyl esters chosen as surrogates for the long-chain esters that are primary constituents of biodiesel fuels. The principal goals of these studies were: (1) show how fuel-specific structural differences including degree of unsaturation, linear vs. branched chain structures, and methoxy vs. ethoxy functions affect fueldestruction pathways, (2) understand the chemistry leading to potential increases in the emissions of hazardous air pollutants including aldehydes and ketones inherent in the use of biodiesel fuels, and (3) define the key chemical reaction mechanisms responsible for observed reductions in polycyclic aromatic hydrocarbons and particulate matter when oxygenated fuels are used as replacements for conventional fuels.
Date: February 12, 2013
Creator: Hansen, Nils
Object Type: Report
System: The UNT Digital Library
Entropy-Bayesian Inversion of Time-Lapse Tomographic GPR data for Monitoring Dielectric Permittivity and Soil Moisture Variations (open access)

Entropy-Bayesian Inversion of Time-Lapse Tomographic GPR data for Monitoring Dielectric Permittivity and Soil Moisture Variations

In this study, we evaluate the possibility of monitoring soil moisture variation using tomographic ground penetrating radar travel time data through Bayesian inversion, which is integrated with entropy memory function and pilot point concepts, as well as efficient sampling approaches. It is critical to accurately estimate soil moisture content and variations in vadose zone studies. Many studies have illustrated the promise and value of GPR tomographic data for estimating soil moisture and associated changes, however, challenges still exist in the inversion of GPR tomographic data in a manner that quantifies input and predictive uncertainty, incorporates multiple data types, handles non-uniqueness and nonlinearity, and honors time-lapse tomograms collected in a series. To address these challenges, we develop a minimum relative entropy (MRE)-Bayesian based inverse modeling framework that non-subjectively defines prior probabilities, incorporates information from multiple sources, and quantifies uncertainty. The framework enables us to estimate dielectric permittivity at pilot point locations distributed within the tomogram, as well as the spatial correlation range. In the inversion framework, MRE is first used to derive prior probability distribution functions (pdfs) of dielectric permittivity based on prior information obtained from a straight-ray GPR inversion. The probability distributions are then sampled using a Quasi-Monte Carlo (QMC) …
Date: February 12, 2013
Creator: Hou, Z; Terry, N; Hubbard, S S & Csatho, B
Object Type: Report
System: The UNT Digital Library
Beowawe Bottoming Binary Unit - Final Technical Report for EE0002856 (open access)

Beowawe Bottoming Binary Unit - Final Technical Report for EE0002856

This binary plant is the first high-output refrigeration based waste heat recovery cycle in the industry. Its working fluid is environmentally friendly and as such, the permits that would be required with a butane based cycle are not necessary. The unit is modularized, meaning that the unit’s individual skids were assembled in another location and were shipped via truck to the plant site. This project proves the technical feasibility of using low temperature brine The development of the unit led to the realization of low temperature, high output, and environmentally friendly heat recovery systems through domestic research and engineering. The project generates additional renewable energy for Nevada, resulting in cleaner air and reduced carbon dioxide emissions. Royalty and tax payments to governmental agencies will increase, resulting in reduced financial pressure on local entities. The major components of the unit were sourced from American companies, resulting in increased economic activity throughout the country.
Date: February 12, 2013
Creator: McDonald, Dale Edward
Object Type: Report
System: The UNT Digital Library