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Note on Graphite Oxidation by Oxygen and Moisture (open access)

Note on Graphite Oxidation by Oxygen and Moisture

Simplified equations of graphite oxidation are reviewed for semi-infinite slab, finite slab, and cylinder geometries, using the principal assumptions of linearized oxidation kinetics and quasi-steady state oxidation profile. All equations are coupled to a general surface mass transfer boundary condition. The equations include those for oxidant concentration distribution, surface oxidation rate, burnoff profile, and oxidation efficiency. This review also covers some areas that may not be well recognized. The key role of the effective diffusivity is highlighted, with a brief review of measured values. The temperature-dependence of the surface oxidation rate is shown to be more complex than usually shown for the diffusion-affected zone. Assumption of linear kinetics permits ready estimation of equilibration time for development of the quasi-steady burnoff profile. In addition, approximations for the time-steady hydrogen concentration profiles are developed for the case of oxidation by H2O. All cited methods can be readily evaluated by spreadsheet calculation.
Date: February 1, 2009
Creator: Wichner, Robert; Burchell, Timothy D & Contescu, Cristian I
Object Type: Report
System: The UNT Digital Library
Computer Simulations of Edge Effects in a Small-Area Mesa N-P Junction Diodes: Preprint (open access)

Computer Simulations of Edge Effects in a Small-Area Mesa N-P Junction Diodes: Preprint

In this work, computer simulations are used to determine the influence of edge conditions on the overall performance of mesa diodes under dark and illuminated conditions. In particular, we examine the effect of edge shape on the I-V characteristics of the diode.
Date: February 1, 2009
Creator: Appel, J.; Sopori, B. & Ravindra, N. M.
Object Type: Article
System: The UNT Digital Library
Comparisons of the MINOS Near and Far Detector Readout Systems at a Test Beam (open access)

Comparisons of the MINOS Near and Far Detector Readout Systems at a Test Beam

MINOS is a long baseline neutrino oscillation experiment that uses two detectors separated by 734 km. The readout systems used for the two detectors are different and have to be independently calibrated. To verify and make a direct comparison of the calibrated response of the two readout systems, test beam data were acquired using a smaller calibration detector. This detector was simultaneously instrumented with both readout systems and exposed to the CERN PS T7 test beam. Differences in the calibrated response of the two systems are shown to arise from differences in response non-linearity, photomultiplier tube crosstalk, and threshold effects at the few percent level. These differences are reproduced by the Monte Carlo (MC) simulation to better than 1% and a scheme that corrects for these differences by calibrating the MC to match the data in each detector separately is presented. The overall difference in calorimetric response between the two readout systems is shown to be consistent with zero to a precision of 1.3% in data and 0.3% in MC with no significant energy dependence.
Date: February 1, 2009
Creator: Cabrera, A.; U., /Oxford; Adamson, P.; London, /University Coll.; Barker, M.; U., /Oxford et al.
Object Type: Article
System: The UNT Digital Library
Clean Cities Now, Vol. 13, No.1 - February 2009 (Brochure) (open access)

Clean Cities Now, Vol. 13, No.1 - February 2009 (Brochure)

Clean Cities Now is the official newsletter of DOE's Clean Cities program. It includes articles on coalition activities, fleet and stakeholder success stories, and helpful resources.
Date: February 1, 2009
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Light-Induced Passivation of Si by Iodine Ethanol Solution: Preprint (open access)

Light-Induced Passivation of Si by Iodine Ethanol Solution: Preprint

We report on our observations of light-activated passivation of silicon surfaces by iodine-ethanol solution.
Date: February 1, 2009
Creator: Sopori, B.; Rupnowski, P.; Appel, J.; Guhaabiswas, D. & Anderson-Jackson, L.
Object Type: Article
System: The UNT Digital Library
Technology, Performance, and Market Report of Wind-Diesel Applications for Remote and Island Communities: Preprint (open access)

Technology, Performance, and Market Report of Wind-Diesel Applications for Remote and Island Communities: Preprint

This paper describes the current status of wind-diesel technology and its applications, the current research activities, and the remaining system technical and commercial challenges. System architectures, dispatch strategies, and operating experience from a variety of wind-diesel systems will be discussed, as well as how recent development to explore distributed energy generation solutions for wind generation can benefit from the performance experience of operating systems. The paper also includes a detailed discussion of the performance of wind-diesel applications in Alaska, where 10 wind-diesel stations are operating and additional systems are currently being implemented. Additionally, because this application represents an international opportunity, a community of interest committed to sharing technical and operating developments is being formed. The authors hope to encourage this expansion while allowing communities and nations to investigate the wind-diesel option for reducing their dependence on diesel-driven energy sources.
Date: February 1, 2009
Creator: Baring-Gould, I. & Dabo, M.
Object Type: Article
System: The UNT Digital Library
Search for the Production of Narrow t anti-b Resonances in 1.9 fb-1 of p anti-p Collisions at s**(1/2) = 1.96-TeV (open access)

Search for the Production of Narrow t anti-b Resonances in 1.9 fb-1 of p anti-p Collisions at s**(1/2) = 1.96-TeV

We present new limits on resonant tb production in ppbar collisions at sqrt(s) = 1.96 TeV, using 1.9 fb{sup -1} of data recorded with the CDF II detector at the Fermilab Tevatron. We reconstruct a putative tb mass in events with a lepton, neutrino candidate, and two or three jets, and search for anomalous tb production as modeled by W{prime} {yields} tb. We set a new limit on a right-handed W{prime} with standard model-like coupling, excluding any mass below 800 GeV at 95% C.L. For any narrow W{prime}-like state with mass above 800 GeV, the cross-section is found to be less than 0.28 pb at 95% C.L. We also present an exclusion of the W{prime} coupling strength versus W{prime} mass.
Date: February 1, 2009
Creator: Aaltonen, T.; Phys., /Helsinki Inst. of; Adelman, J.; /Chicago U., EFI; Akimoto, T.; U., /Tsukuba et al.
Object Type: Article
System: The UNT Digital Library
Phase I Transport Model of Corrective Action Units 101 and 102: Central and Western Pahute Mesa, Nevada Test Site, Nye County, Nevada with Errata Sheet 1, 2, 3, Revision 1 (open access)

Phase I Transport Model of Corrective Action Units 101 and 102: Central and Western Pahute Mesa, Nevada Test Site, Nye County, Nevada with Errata Sheet 1, 2, 3, Revision 1

As prescribed in the Pahute Mesa Corrective Action Investigation Plan (CAIP) (DOE/NV, 1999) and Appendix VI of the Federal Facility Agreement and Consent Order (FFACO) (1996, as amended February 2008), the ultimate goal of transport analysis is to develop stochastic predictions of a contaminant boundary at a specified level of uncertainty. However, because of the significant uncertainty of the model results, the primary goal of this report was modified through mutual agreement between the DOE and the State of Nevada to assess the primary model components that contribute to this uncertainty and to postpone defining the contaminant boundary until additional model refinement is completed. Therefore, the role of this analysis has been to understand the behavior of radionuclide migration in the Pahute Mesa (PM) Corrective Action Unit (CAU) model and to define, both qualitatively and quantitatively, the sensitivity of such behavior to (flow) model conceptualization and (flow and transport) parameterization.
Date: February 1, 2009
Creator: Ruskauff, Greg
Object Type: Report
System: The UNT Digital Library
Identification of Strategies to Leverage Public and Private Resources for National Security Workforce Development (open access)

Identification of Strategies to Leverage Public and Private Resources for National Security Workforce Development

This report documents the identification of strategies to leverage public and private resources for the development of an adequate national security workforce as part of the National Security Preparedness Project (NSPP).There are numerous efforts across the United States to develop a properly skilled and trained national security workforce. Some of these efforts are the result of the leveraging of public and private dollars. As budget dollars decrease and the demand for a properly skilled and trained national security workforce increases, it will become even more important to leverage every education and training dollar. The leveraging of dollars serves many purposes. These include increasing the amount of training that can be delivered and therefore increasing the number of people reached, increasing the number and quality of public/private partnerships, and increasing the number of businesses that are involved in the training of their future workforce.
Date: February 1, 2009
Creator: unknown
Object Type: Text
System: The UNT Digital Library
Determination of Ideal Broth Formulations Needed to Prepare Hydrous Aluminum Oxide Microspheres via the Internal Gelation Process (open access)

Determination of Ideal Broth Formulations Needed to Prepare Hydrous Aluminum Oxide Microspheres via the Internal Gelation Process

A simple test-tube methodology was used to determine optimum process parameters for preparing hydrous aluminum oxide microspheres by the internal gelation process. Broth formulations of aluminum, hexamethylenetetramine, and urea were found that can be used to prepare hydrous aluminum oxide gel spheres in the temperature range of 60-90 C. A few gel-forming runs were made in which microspheres were prepared with some of these formulations in order to equate the test-tube gelation times with actual gelation times. These preparations confirmed that the test-tube methodology is reliable for determining the ideal broths.
Date: February 1, 2009
Creator: Collins, Jack Lee & Pye, S. L.
Object Type: Report
System: The UNT Digital Library
Planar LTCC transformers for high voltage flyback converters: Part II. (open access)

Planar LTCC transformers for high voltage flyback converters: Part II.

This paper is a continuation of the work presented in SAND2007-2591 'Planar LTCC Transformers for High Voltage Flyback Converters'. The designs in that SAND report were all based on a ferrite tape/dielectric paste system originally developed by NASCENTechnoloy, Inc, who collaborated in the design and manufacturing of the planar LTCC flyback converters. The output/volume requirements were targeted to DoD application for hard target/mini fuzing at around 1500 V for reasonable primary peak currents. High voltages could be obtained but with considerable higher current. Work had begun on higher voltage systems and is where this report begins. Limits in material properties and processing capabilities show that the state-of-the-art has limited our practical output voltage from such a small part volume. In other words, the technology is currently limited within the allowable funding and interest.
Date: February 1, 2009
Creator: Schofield, Daryl (NASCENTechnology, Inc., Watertown, SD); Schare, Joshua M., Ph.D.; Slama, George (NASCENTechnology, Inc., Watertown, SD) & Abel, David (NASCENTechnology, Inc., Watertown, SD)
Object Type: Report
System: The UNT Digital Library
Annual Waste Minimization Summary Report, Calendar Year 2008 (open access)

Annual Waste Minimization Summary Report, Calendar Year 2008

This report summarizes the waste minimization efforts undertaken by National Security Technologies, LLC (NSTec), for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office (NNSA/NSO), during calendar year 2008.
Date: February 1, 2009
Creator: National Security Technologies, LLC
Object Type: Report
System: The UNT Digital Library
Determination of Ideal Broth Formulations Needed to Prepare Hydrous Cerium Oxide Microspheres via the Internal Gelation Process (open access)

Determination of Ideal Broth Formulations Needed to Prepare Hydrous Cerium Oxide Microspheres via the Internal Gelation Process

A simple test tube methodology was used to determine optimum process parameters for preparing hydrous cerium oxide microspheres via the internal gelation process.1 Broth formulations of cerium ammonium nitrate [(NH4)2Ce(NO3)6], hexamethylenetetramine, and urea were found that can be used to prepare hydrous cerium oxide gel spheres in the temperature range of 60 to 90 C. A few gel-forming runs were made in which microspheres were prepared with some of these formulations to be able to equate the test-tube gelation times to actual gelation times. These preparations confirmed that the test-tube methodology is reliable for determining the ideal broth formulations.
Date: February 1, 2009
Creator: Collins, Jack Lee & Chi, Anthony
Object Type: Report
System: The UNT Digital Library
Determination of Ideal Broth Formulations Needed to Prepare Hydrous Hafnium Oxide Microspheres via the Internal Gelation Process (open access)

Determination of Ideal Broth Formulations Needed to Prepare Hydrous Hafnium Oxide Microspheres via the Internal Gelation Process

A simple test-tube methodology was used to determine optimum process parameters for preparing hydrous hafnium oxide microspheres by the internal gelation process. Broth formulations of hafnyl chloride [HfOCl{sub 2}], hexamethylenetetramine, and urea were found that can be used to prepare hydrous hafnium oxide gel spheres in the temperature range of 70-90 C. A few gel-forming runs were made in which microspheres were prepared with some of these formulations in order to equate the test-tube gelation times with actual gelation times. These preparations confirmed that the test-tube methodology is reliable for determining the ideal broths.
Date: February 1, 2009
Creator: Collins, Jack Lee; Hunt, Rodney Dale & Simmerman, S. G.
Object Type: Report
System: The UNT Digital Library
Measurement of the B/s0 lifetime in B/s0 --> K+ K- decays (open access)

Measurement of the B/s0 lifetime in B/s0 --> K+ K- decays

A method is presented to simultaneously separate the contributions to a sample of B{sub (s)}{sup 0} {yields} h{sup +}h{sup {prime}-} decays, where h = {pi} or K, and measure the B meson lifetimes in the sample while correcting for the bias in the lifetime distributions due to the hadronic trigger at the CDF experiment. Using 1 fb{sup -1} of data collected at CDF the B{sup 0} lifetime is measured as {tau}{sub B{sup 0}} = 1.558{sub -0.047}{sup +0.050}{sub stat} {+-} 0.028{sub syst} ps, in agreement with the world average measurement. The B{sub s}{sup 0} lifetime in the B{sub s}{sup 0} {yields} K{sup +}K{sup -} decay is measured as {tau}{sub B{sub s}{sup 0} {yields} K{sup +}K{sup -}} = 1.51{sub -0.11}{sup +0.13}{sub stat} {+-} 0.04{sub syst} ps. No difference is observed between the lifetime and other measurements of the average B{sub s}{sup 0} lifetime or the lifetime of the light B{sub s}{sup 0} mass eigenstate determined from B{sub s}{sup 0} {yields} J/{psi}{phi} decays. With the assumptions that B{sub s}{sup 0} {yields} K{sup +}K{sup -} is 100% CP-even and that {tau}{sub B{sub s}{sup 0}} = {tau}{sub B{sup 0}} the width difference in the B{sub s}{sup 0} system is determined as {Delta}{Lambda}{sup CP}/{Lambda} = 0.03{sub …
Date: February 1, 2009
Creator: Pounder, Nicola Louise
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Definition of a 5-MW Reference Wind Turbine for Offshore System Development (open access)

Definition of a 5-MW Reference Wind Turbine for Offshore System Development

This report describes a three-bladed, upwind, variable-speed, variable blade-pitch-to-feather-controlled multimegawatt wind turbine model developed by NREL to support concept studies aimed at assessing offshore wind technology.
Date: February 1, 2009
Creator: Jonkman, J.; Butterfield, S.; Musial, W. & Scott, G.
Object Type: Report
System: The UNT Digital Library
Annual Transportation Report for Radioactive Waste Shipments to and from the Nevada Test Site (open access)

Annual Transportation Report for Radioactive Waste Shipments to and from the Nevada Test Site

In February 1997, the U.S. Department of Energy (DOE), Nevada Operations Office (now known as the Nevada Site Office) issued the Mitigation Action Plan which addressed potential impacts described in the “Final Environmental Impact Statement for the Nevada Test Site and Off-Site Locations in the State of Nevada” (DOE/EIS 0243). The U.S. Department of Energy, Nevada Operations Office committed to several actions, including the preparation of an annual report, which summarizes waste shipments to and from the Nevada Test Site (NTS) Radioactive Waste Management Site (RWMS) at Area 5 and Area 3. No shipments were disposed of at Area 3 in fiscal year (FY) 2008. This document satisfies requirements regarding low-level radioactive waste (LLW) and mixed low-level radioactive waste (MLLW) transported to or from the NTS during FY 2008. No transuranic (TRU) waste shipments were made from or to the NTS during FY 2008.
Date: February 1, 2009
Creator: United States. National Nuclear Security Administration. Nevada Site Office.
Object Type: Report
System: The UNT Digital Library
Assess the Efficacy of an Aerial Distant Observer Tool Capable of Rapid Analysis of Large Sections of Collector Fields, FY 2008 CSP Milestone Report, September 2008 (open access)

Assess the Efficacy of an Aerial Distant Observer Tool Capable of Rapid Analysis of Large Sections of Collector Fields, FY 2008 CSP Milestone Report, September 2008

We assessed the feasibility of developing an aerial Distant Observer optical characterization tool for collector fields in concentrating solar power plants.
Date: February 1, 2009
Creator: Jorgensen, G.; Burkholder, F.; Gray, A. & Wendelin, T.
Object Type: Report
System: The UNT Digital Library
Gearbox Modeling and Load Simulation of a Baseline 750-kW Wind Turbine Using State-of-the-Art Simulation Codes (open access)

Gearbox Modeling and Load Simulation of a Baseline 750-kW Wind Turbine Using State-of-the-Art Simulation Codes

This report discusses the causes for premature wind turbine gearbox failure and determining a method for revealing the missing loading conditions relevant to the gearbox design process.
Date: February 1, 2009
Creator: Oyague, F.
Object Type: Report
System: The UNT Digital Library
Analysis of the Reuse of Uranium Recovered from the Reprocessing of Commercial LWR Spent Fuel (open access)

Analysis of the Reuse of Uranium Recovered from the Reprocessing of Commercial LWR Spent Fuel

This report provides an analysis of the factors involved in the reuse of uranium recovered from commercial light-water-reactor (LWR) spent fuels (1) by reenrichment and recycling as fuel to LWRs and/or (2) by recycling directly as fuel to heavy-water-reactors (HWRs), such as the CANDU (registered trade name for the Canadian Deuterium Uranium Reactor). Reuse is an attractive alternative to the current Advanced Fuel Cycle Initiative (AFCI) Global Nuclear Energy Partnership (GNEP) baseline plan, which stores the reprocessed uranium (RU) for an uncertain future or attempts to dispose of it as 'greater-than-Class C' waste. Considering that the open fuel cycle currently deployed in the United States already creates a huge excess quantity of depleted uranium, the closed fuel cycle should enable the recycle of the major components of spent fuel, such as the uranium and the hazardous, long-lived transuranic (TRU) actinides, as well as the managed disposal of fission product wastes. Compared with the GNEP baseline scenario, the reuse of RU in the uranium fuel cycle has a number of potential advantages: (1) avoidance of purchase costs of 11-20% of the natural uranium feed; (2) avoidance of disposal costs for a large majority of the volume of spent fuel that is …
Date: February 1, 2009
Creator: DelCul, Guillermo D; Trowbridge, Lee D; Renier, John-Paul; Ellis, Ronald James; Williams, Kent Alan; Spencer, Barry B et al.
Object Type: Report
System: The UNT Digital Library
Investigations of the small-scale thermal behavior of sol-gel thermites. (open access)

Investigations of the small-scale thermal behavior of sol-gel thermites.

Sol-gel thermites, formulated from nanoporous oxides and dispersed fuel particles, may provide materials useful for small-scale, intense thermal sources, but understanding the factors affecting performance is critical prior to use. Work was conducted on understanding the synthesis conditions, thermal treatments, and additives that lead to different performance characteristics in iron oxide sol-gel thermites. Additionally, the safety properties of sol-gel thermites were investigated, especially those related to air sensitivity. Sol-gel thermites were synthesized using a variety of different techniques and there appear to be many viable routes to relatively equivalent thermites. These thermites were subjected to several different thermal treatments under argon in a differential scanning calorimeter, and it was shown that a 65 C hold for up to 200 minutes was effective for the removal of residual solvent, thus preventing boiling during the final thermal activation step. Vacuum-drying prior to this heating was shown to be even more effective at removing residual solvent. The addition of aluminum and molybdenum trioxide (MoO{sub 3}) reduced the total heat release per unit mass upon exposure to air, probably due to a decrease in the amount of reduced iron oxide species in the thermite. For the thermal activation step of heat treatment, three different …
Date: February 1, 2009
Creator: Warren, Mial E.; Farrow, Matthew & Tappan, Alexander Smith
Object Type: Report
System: The UNT Digital Library
Potential for Reducing Blade-Tip Acoustic Emissions for Small Wind Turbines: June 1, 2007 - July 31, 2008 (open access)

Potential for Reducing Blade-Tip Acoustic Emissions for Small Wind Turbines: June 1, 2007 - July 31, 2008

This report provides results of wind tunnel aroacoustic tests conducted on a small wind turbine blade in the open-jet test section of the Georgia Tech Research Institute Flight Simulation Facility.
Date: February 1, 2009
Creator: Migliore, P.
Object Type: Report
System: The UNT Digital Library
Providing Reliability Services through Demand Response: A Prelimnary Evaluation of the Demand Response Capabilities of Alcoa Inc. (open access)

Providing Reliability Services through Demand Response: A Prelimnary Evaluation of the Demand Response Capabilities of Alcoa Inc.

Demand response is the largest underutilized reliability resource in North America. Historic demand response programs have focused on reducing overall electricity consumption (increasing efficiency) and shaving peaks but have not typically been used for immediate reliability response. Many of these programs have been successful but demand response remains a limited resource. The Federal Energy Regulatory Commission (FERC) report, 'Assessment of Demand Response and Advanced Metering' (FERC 2006) found that only five percent of customers are on some form of demand response program. Collectively they represent an estimated 37,000 MW of response potential. These programs reduce overall energy consumption, lower green house gas emissions by allowing fossil fuel generators to operate at increased efficiency and reduce stress on the power system during periods of peak loading. As the country continues to restructure energy markets with sophisticated marginal cost models that attempt to minimize total energy costs, the ability of demand response to create meaningful shifts in the supply and demand equations is critical to creating a sustainable and balanced economic response to energy issues. Restructured energy market prices are set by the cost of the next incremental unit of energy, so that as additional generation is brought into the market, the …
Date: February 1, 2009
Creator: Starke, Michael R; Kirby, Brendan J; Kueck, John D; Todd, Duane; Caulfield, Michael & Helms, Brian
Object Type: Report
System: The UNT Digital Library
Effect of Intake Air Filter Condition on Vehicle Fuel Economy (open access)

Effect of Intake Air Filter Condition on Vehicle Fuel Economy

The U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy and the U.S. Environmental Protection Agency (EPA) jointly maintain a fuel economy website (www.fueleconomy.gov), which helps fulfill their responsibility under the Energy Policy Act of 1992 to provide accurate fuel economy information [in miles per gallon (mpg)] to consumers. The site provides information on EPA fuel economy ratings for passenger cars and light trucks from 1985 to the present and other relevant information related to energy use such as alternative fuels and driving and vehicle maintenance tips. In recent years, fluctuations in the price of crude oil and corresponding fluctuations in the price of gasoline and diesel fuels have renewed interest in vehicle fuel economy in the United States. (User sessions on the fuel economy website exceeded 20 million in 2008 compared to less than 5 million in 2004 and less than 1 million in 2001.) As a result of this renewed interest and the age of some of the references cited in the tips section of the website, DOE authorized the Oak Ridge National Laboratory (ORNL) Fuels, Engines, and Emissions Research Center (FEERC) to initiate studies to validate and improve these tips. This report documents a …
Date: February 1, 2009
Creator: Norman, Kevin M; Huff, Shean P & West, Brian H
Object Type: Report
System: The UNT Digital Library