Waste Tank Heels and Heel Simulants (open access)

Waste Tank Heels and Heel Simulants

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Date: May 18, 2009
Creator: Barton, W. B.
Object Type: Article
System: The UNT Digital Library
Feedback Techniques and Ecloud Instabilites - Design Estimates (open access)

Feedback Techniques and Ecloud Instabilites - Design Estimates

The SPS at high intensities exhibits transverse single-bunch instabilities with signatures consistent with an Ecloud driven instability. While the SPS has a coupled-bunch transverse feedback system, control of Ecloud-driven motion requires a much wider control bandwidth capable of sensing and controlling motion within each bunched beam. This paper draws beam dynamics data from the measurements and simulations of this SPS instability, and estimates system requirements for a feedback system with 2-4 GS/sec. sampling rates to damp Ecloud-driven transverse motion in the SPS at intensities desired for high-current LHC operation.
Date: May 18, 2009
Creator: Fox, J. D.; Mastorides, T.; Ndabashimiye, G.; Rivetta, C.; Winkle, D. Van; Byrd, J. et al.
Object Type: Article
System: The UNT Digital Library
Final report for "Characterization of Fine Particulate Matter (PM) and secondary PM Precursor Gases in the Mexico City Metropolitan Area" (open access)

Final report for "Characterization of Fine Particulate Matter (PM) and secondary PM Precursor Gases in the Mexico City Metropolitan Area"

The objectives of this funded project were (a) to further analyze the data collected by our group and collaborators in Mexico City during the MCMA-2003 field campaign, with the goal of further our understanding of aerosol sources and processes; and (b) to deploy several advanced instruments, including the newly developed high-resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and thermal-denuder (TD), during the MILAGRO/MAX-Mex/MCMA-2006 field campaign, and to analyze those data (together with the 2003 data) to provide additional insights on the formation and transformation of aerosols in the Mexico City area. These goals were addressed in collaboration with our project partners, MIT/Molina Center, and Aerodyne Research. Overall this project was very successful, resulting on 22+ journal papers including six “highly cited papers” and three papers that are the most cited in their respective journals (out of several thousand papers) since the year in which they were published. Multiple discoveries, such as the the underestimation of SOA in urban areas even for short photochemical ages, the demonstration that urban POA is of similar or higher volatility than urban SOA, and the first analysis of organic aerosol elemental composition in real-time have been recently published. Several dozen presentations at major US and international …
Date: May 18, 2009
Creator: Jimenez, Jose-Luis
Object Type: Report
System: The UNT Digital Library
Application of Self-Propagating High Temperature Synthesis to the Fabrication of Actinide Bearing Nitride and Other Ceramic Nuclear Fuels (open access)

Application of Self-Propagating High Temperature Synthesis to the Fabrication of Actinide Bearing Nitride and Other Ceramic Nuclear Fuels

The high vapor pressures of americium (Am) and americium nitride (AmN) are cause for concern in producing nitride ceramic nuclear fuel that contains Am. Along with the problem of Am retention during the sintering phases of current processing methods, are additional concerns of producing a consistent product of desirable homogeneity, density and porosity. Similar difficulties have been experienced during the laboratory scale process development stage of producing metal alloys containing Am wherein compact powder sintering methods had to be abandoned. Therefore, there is an urgent need to develop a low-temperature or low–heat fuel fabrication process for the synthesis of Am-containing ceramic fuels. Self-propagating high temperature synthesis (SHS), also called combustion synthesis, offers such an alternative process for the synthesis of Am nitride fuels. Although SHS takes thermodynamic advantage of the high combustion temperatures of these exothermic SHS reactions to synthesize the required compounds, the very fast heating, reaction and cooling rates can kinetically generate extremely fast reaction rates and facilitate the retention of volatile species within the rapidly propagating SHS reaction front. The initial objective of the research program is to use Mn as the surrogate for Am to synthesize a reproducible, dense, high quality Zr-Mn-N ceramic compound. Having determined …
Date: May 18, 2009
Creator: John J. Moore, Douglas E. Burkes, Collin D. Donohoue, Marissa M. Reigel, J. Rory Kennedy
Object Type: Report
System: The UNT Digital Library
Residential Electricity Demand in China -- Can Efficiency Reverse the Growth? (open access)

Residential Electricity Demand in China -- Can Efficiency Reverse the Growth?

The time when energy-related carbon emissions come overwhelmingly from developed countries is coming to a close. China has already overtaken the United States as the world's leading emitter of greenhouse gas emissions. The economic growth that China has experienced is not expected to slow down significantly in the long term, which implies continued massive growth in energy demand. This paper draws on the extensive expertise from the China Energy Group at LBNL on forecasting energy consumption in China, but adds to it by exploring the dynamics of demand growth for electricity in the residential sector -- and the realistic potential for coping with it through efficiency. This paper forecasts ownership growth of each product using econometric modeling, in combination with historical trends in China. The products considered (refrigerators, air conditioners, fans, washing machines, lighting, standby power, space heaters, and water heating) account for 90percent of household electricity consumption in China. Using this method, we determine the trend and dynamics of demandgrowth and its dependence on macroeconomic drivers at a level of detail not accessible by models of a more aggregate nature. In addition, we present scenarios for reducing residential consumption through efficiency measures defined at the product level. The research …
Date: May 18, 2009
Creator: Letschert, Virginie; McNeil, Michael A. & Zhou, Nan
Object Type: Article
System: The UNT Digital Library
Advances in full field microscopy with table-top soft x-ray lasers (open access)

Advances in full field microscopy with table-top soft x-ray lasers

We describe recent advances in the demonstration of table-top full field microscopes that use soft x-ray lasers for illumination. We have achieved wavelength resolution and single shot exposure operation with a very compact 46.9 nm microscope based on a desk-top size capillary discharge laser. This {lambda}-46.9 nm microscope has been used to capture full field images of a variety of nanostructure systems and surfaces. In a separate development we have demonstrated a zone plate microscope that uses {lambda}=13.2 nm laser illumination to image absorption defects in an extreme ultraviolet lithography (EUVL) mask in the same geometry used in a 4x demagnification EUVL stepper. Characterization of the microscope’s transfer function shows it can resolve 55 nm half period patterns. With these capabilities, the {lambda}-13.2 nm microscope is well suited for evaluation of pattern and defect printability of EUVL masks for the 22 nm node.
Date: May 18, 2009
Creator: Menoni, C. S.; Brizuela, F.; Wang, Y.; Brewer, C. A.; Luther, B. M.; Pedaci, F. et al.
Object Type: Article
System: The UNT Digital Library
Technical Review of the UNET2D Hydraulic Model (open access)

Technical Review of the UNET2D Hydraulic Model

The Kansas City District of the US Army Corps of Engineers is engaged in a broad range of river management projects that require knowledge of spatially-varied hydraulic conditions such as velocities and water surface elevations. This information is needed to design new structures, improve existing operations, and assess aquatic habitat. Two-dimensional (2D) depth-averaged numerical hydraulic models are a common tool that can be used to provide velocity and depth information. Kansas City District is currently using a specific 2D model, UNET2D, that has been developed to meet the needs of their river engineering applications. This report documents a tech- nical review of UNET2D.
Date: May 18, 2009
Creator: Perkins, William A. & Richmond, Marshall C.
Object Type: Report
System: The UNT Digital Library
Effect of temperature on the complexation of Uranium(VI) with fluoride in aqueous solutions (open access)

Effect of temperature on the complexation of Uranium(VI) with fluoride in aqueous solutions

Complexation of U(VI) with fluoride at elevated temperatures in aqueous solutions was studied by spectrophotometry. Four successive complexes, UO{sub 2}F{sup +}, UO{sub 2}F{sub 2}(aq), UO{sub 2}F{sub 3}{sup -}, and UO{sub 2}F{sub 4}{sup 2-}, were identified, and the stability constants at 25, 40, 55, and 70 C were calculated. The stability of the complexes increased as the temperature was elevated. The enthalpies of complexation at 25 C were determined by microcalorimetry. Thermodynamic parameters indicate that the complexation of U(VI) with fluoride in aqueous solutions at 25 to 70 C is slightly endothermic and entropy-driven. The Specific Ion Interaction (SIT) approach was used to obtain the thermodynamic parameters of complexation at infinite dilution. Structural information on the U(VI)/fluoride complexes was obtained by extended X-ray absorption fine structure spectroscopy.
Date: May 18, 2009
Creator: Tian, Guoxin & Rao, Linfeng
Object Type: Article
System: The UNT Digital Library
Caustic Cleaning for Waste Heel Removal (open access)

Caustic Cleaning for Waste Heel Removal

This report talks about Caustic Cleaning for Waste Heel Removal
Date: May 18, 2009
Creator: W. B Barton
Object Type: Article
System: The UNT Digital Library