Collection
Office of Scientific & Technical Information Technical Reports
7,379
Congressional Research Service Reports
3,330
Defense Base Closure and Realignment Commission
1,004
Government Accountability Office Reports
862
Texas State Publications
318
Texas Attorney General Opinions
107
Texas State Auditor's Office: Reports
68
Texas Register
54
End of Term Publications
47
Federal Communications Commission Record
21
11 More
Country
States
Year
Month
13,225 Matching Results
Results open in a new window/tab.
Embedded Optical Sensors for Thermal Barrier Coatings
None
Date:
December 31, 2006
Creator:
Clarke, David R.
Object Type:
Report
System:
The UNT Digital Library
An Energy Savings Model for the Heat Treatment of Castings
An integrated system of software, databases, and design rules have been developed, verified, and to be marketed to enable quantitative prediction and optimization of the heat treatment of aluminum castings to increase quality, increase productivity, reduce heat treatment cycle times and reduce energy consumption. The software predicts the thermal cycle in critical locations of individual components in a furnace, the evolution of microstructure, and the attainment of properties in heat treatable aluminum alloy castings. The model takes into account the prior casting process and the specific composition of the component. The heat treatment simulation modules can be used in conjunction with software packages for simulation of the casting process. The system is built upon a quantitative understanding of the kinetics of microstructure evolution in complex multicomponent alloys, on a quantitative understanding of the interdependence of microstructure and properties, on validated kinetic and thermodynamic databases, and validated quantitative models.
Date:
December 31, 2006
Creator:
Rong, Y.; Sisson, R.; Morral, J. & Brody, H.
Object Type:
Report
System:
The UNT Digital Library
Enhanced Activity of Nanocrystalline Zeolites for Selective Catalytic Reduction of NOx
Nanocrystalline zeolites with discrete crystal sizes of less than 100 nm have different properties relative to zeolites with larger crystal sizes. Nanocrystalline zeolites have improved mass transfer properties and very large internal and external surface areas that can be exploited for many different applications. The additional external surface active sites and the improved mass transfer properties of nanocrystalline zeolites offer significant advantages for selective catalytic reduction (SCR) catalysis with ammonia as a reductant in coal-fired power plants relative to current zeolite based SCR catalysts. Nanocrystalline NaY was synthesized with a crystal size of 15-20 nm and was thoroughly characterized using x-ray diffraction, electron paramagnetic resonance spectroscopy, nitrogen adsorption isotherms and Fourier Transform Infrared (FT-IR) spectroscopy. Copper ions were exchanged into nanocrystalline NaY to increase the catalytic activity. The reactions of nitrogen dioxides (NO{sub x}) and ammonia (NH{sub 3}) on nanocrystalline NaY and CuY were investigated using FT-IR spectroscopy. Significant conversion of NO{sub 2} was observed at room temperature in the presence of NH{sub 3} as monitored by FT-IR spectroscopy. Copper-exchanged nanocrystalline NaY was more active for NO{sub 2} reduction with NH{sub 3} relative to nanocrystalline NaY.
Date:
December 31, 2006
Creator:
Larson, Sarah C. & Grassian, Vicki H.
Object Type:
Report
System:
The UNT Digital Library
Environmental Solutions FY05: PNNL Contributions to U.S. Department of Energy
The U.S. Department of Energy's mission is to protect the Columbia River, a vital regional asset, and the public in cities and towns near the Site. To make decisions and comply with a complex system of regulations, DOE needs reliable, accurate data about the Site. Where are the contaminants now? At what concentrations? What impact do the contaminants have on people that work on the Site and live nearby? To answer these questions and others, Pacific Northwest National Laboratory scientists collect and analyze thousands of soil, groundwater, surface water, plant, and animal samples. The results are then communicated to DOE through reports and conceptual models.
Date:
December 31, 2006
Creator:
Freshley, Mark D. & Manke, Kristin L.
Object Type:
Report
System:
The UNT Digital Library
Establishment of an Environmental Control Technology Laboratory with a Circulating Fluidized-Bed Combustion System
None
Date:
December 31, 2006
Creator:
Pan, Wei-Ping; Cheng, Zhongxian; Cao, Yan & Smith, John
Object Type:
Report
System:
The UNT Digital Library
Experimental Investigation and High Resolution Simulator of In-Situ Combustion Processes
Accurate simulation of in-situ combustion processes is computationally very challenging because the spatial and temporal scales over which the combustion process takes place are very small. In this current and thirteenth report, we report on our continuing development of a Virtual Kinetic Cell model and our continuing experimental program.
Date:
December 31, 2006
Creator:
Gerritsen, Margot & Kovscek, Anthony R.
Object Type:
Report
System:
The UNT Digital Library
Exploitation and Optimization of Reservoir Performance in Hunton Formation, Oklahoma
None
Date:
December 31, 2006
Creator:
Kelkar, Mohan
Object Type:
Report
System:
The UNT Digital Library
Field Demonstration of a Membrane Process to Separate Nitrogen from Natural Gas
None
Date:
December 31, 2006
Creator:
Lokhandwala, Kaaeid
Object Type:
Report
System:
The UNT Digital Library
Final Progress Report for the activity called AMO2010 committee
The committee was charged to produce a comprehensive report on the status of AMO Science. The committee was charged to produce a report that: 1. Reviewed the field of AMO science, emphasize recent accomplishments, and identify new opportunities and compelling scientific questions; 2. Identified the impact of AMO science on other scientific fields, emerging technologies, and national needs; 3. Identified future workforce, societal and educational needs for AMO science; and 4. Made recommendations on how the US research enterprise might realize the full potential of AMO science. The committee also produced an intermediate report addressing key research issues and themes facing the research community.
Date:
December 31, 2006
Creator:
Shapero, Donald & Moloney, Michael
Object Type:
Report
System:
The UNT Digital Library
Functionally Graded Cathodes for Solid Oxide Fuel Cells
One primary suspected cause of long-term performance degradation of solid oxide fuels (SOFCs) is the accumulation of chromium (Cr) species at or near the cathode/electrolyte interface due to reactive Cr molecules originating from Cr-containing components (such as the interconnect) in fuel cell stacks. To date, considerable efforts have been devoted to the characterization of cathodes exposed to Cr sources; however, little progress has been made because a detailed understanding of the chemistry and electrochemistry relevant to the Cr-poisoning processes is still lacking. This project applied multiple characterization methods - including various Raman spectroscopic techniques and various electrochemical performance measurement techniques - to elucidate and quantify the effect of Cr-related electrochemical degradation at the cathode/electrolyte interface. Using Raman microspectroscopy the identity and location of Cr contaminants (SrCrO{sub 4}, (Mn/Cr){sub 3}O{sub 4} spinel) have been observed in situ on an LSM cathode. These Cr contaminants were shown to form chemically (in the absence of current flowing through the cell) at temperatures as low as 625 C. While SrCrO{sub 4} and (Mn/Cr){sub 3}O{sub 4} spinel must preferentially form on LSM, since the LSM supplies the Sr and Mn cations necessary for these compounds, LSM was also shown to be an active site for …
Date:
December 31, 2006
Creator:
Abernathy, Harry & Liu, Meilin
Object Type:
Report
System:
The UNT Digital Library
FY 1999 Progress Report on: Potential Groundwater Recharge from the Infiltration of Surface Runoff in Cold and Dry Creeks
The volume of water available for groundwater recharge through the infiltration of surface runoff in Cold and Dry Creeks was estimated for a 100-year storm and the Probable Maximum Precipitation (PMP) of Skaggs and Walters (1981). A 100-year, 7-day design storm was developed from 40 years of precipitation data measured at the Hanford Meteorological Station (HMS). Runoff measured in Upper Cold Creek was used with HMS precipitation data to calculate curve numbers for the Soil Conservation Service rainfall-runoff model. The estimated water available for recharge from surface runoff produced by the 100-year storm is 3-6 times the annual recharge rate from direct infiltration of precipitation over the Hanford Site. Potential recharge from the PMP is 7-11 times the annual volume of direct recharge.
Date:
December 31, 2006
Creator:
Wigmosta, Mark S. & Guensch, Gregory R.
Object Type:
Report
System:
The UNT Digital Library
Gas Storage Technology Consortium
None
Date:
December 31, 2006
Creator:
Morrison, Joel L. & Elder, Sharon L.
Object Type:
Report
System:
The UNT Digital Library
Geomechanical Performance of Hydrate-Bearing Sediments in Offshore Environments
The main objective of this study is to develop the necessary knowledge base and quantitative predictive capability for the description of geomechanical performance of hydrate bearing sediments (hereafter referred to as HBS) in oceanic environments. The focus is on the determination of the envelope of hydrate stability under conditions typical of those related to the construction and operation of offshore platforms. To achieve this objective, we have developed a robust numerical simulator of hydrate behavior in geologic media by coupling a reservoir model with a commercial geomechanical code. To be sure our geomechanical modeling is realistic, we are also investigating the geomechanical behavior of oceanic HBS using pore-scale models (conceptual and mathematical) of fluid flow, stress analysis, and damage propagation. In Phase II of the project, we will review all published core data and generate additional core data to verify the models. To generate data for our models, we are using data from the literature and we will be conducting laboratory studies in 2007 that generate data to (1) evaluate the conceptual pore-scale models, (2) calibrate the mathematical models, (3) determine dominant relations and critical parameters defining the geomechanical behavior of HBS, and (4) establish relationships between the geomechanical status …
Date:
December 31, 2006
Creator:
Holditch, Stephen A.
Object Type:
Report
System:
The UNT Digital Library
Graduate Automotive Technology Education (GATE) Program: Center of Automotive Technology Excellence in Advanced Hybrid Vehicle Technology at West Virginia University
This report summarizes the technical and educational achievements of the Graduate Automotive Technology Education (GATE) Center at West Virginia University (WVU), which was created to emphasize Advanced Hybrid Vehicle Technology. The Center has supported the graduate studies of 17 students in the Department of Mechanical and Aerospace Engineering and the Lane Department of Computer Science and Electrical Engineering. These students have addressed topics such as hybrid modeling, construction of a hybrid sport utility vehicle (in conjunction with the FutureTruck program), a MEMS-based sensor, on-board data acquisition for hybrid design optimization, linear engine design and engine emissions. Courses have been developed in Hybrid Vehicle Design, Mobile Source Powerplants, Advanced Vehicle Propulsion, Power Electronics for Automotive Applications and Sensors for Automotive Applications, and have been responsible for 396 hours of graduate student coursework. The GATE program also enhanced the WVU participation in the U.S. Department of Energy Student Design Competitions, in particular FutureTruck and Challenge X. The GATE support for hybrid vehicle technology enhanced understanding of hybrid vehicle design and testing at WVU and encouraged the development of a research agenda in heavy-duty hybrid vehicles. As a result, WVU has now completed three programs in hybrid transit bus emissions characterization, and WVU …
Date:
December 31, 2006
Creator:
Clark, Nigle N.
Object Type:
Report
System:
The UNT Digital Library
Heavy Truck Clean Diesel Cooperative Research Program
This report is the final report for the Department of Energy on the Heavy Truck Engine Program (Contract No. DE-FC05-00OR22806) also known as Heavy Truck Clean Diesel (HTCD) Program. Originally, this was scoped to be a $38M project over 5 years, to be 50/50 co-funded by DOE and Caterpillar. The program started in June 2000. During the program the timeline was extended to a sixth year. The program completed in December 2006. The program goal was to develop and demonstrate the technologies required to enable compliance with the 2007 and 2010 (0.2g/bhph NOx, 0.01g/bhph PM) on-highway emission standards for Heavy Duty Trucks in the US with improvements in fuel efficiency compared to today's engines. Thermal efficiency improvement from a baseline of 43% to 50% was targeted.
Date:
December 31, 2006
Creator:
Milam, David
Object Type:
Report
System:
The UNT Digital Library
High Altitude Aerial Natural Gas Leak Detection System
The objective of this program was to develop and demonstrate a cost-effective and power-efficient advanced standoff sensing technology able to detect and quantify, from a high-altitude (> 10,000 ft) aircraft, natural gas leaking from a high-pressure pipeline. The advanced technology is based on an enhanced version of the Remote Methane Leak Detector (RMLD) platform developed previously by Physical Sciences Inc. (PSI). The RMLD combines a telecommunications-style diode laser, fiber-optic components, and low-cost DSP electronics with the well-understood principles of Wavelength Modulation Spectroscopy (WMS), to indicate the presence of natural gas located between the operator and a topographic target. The transceiver transmits a laser beam onto a topographic target and receives some of the laser light reflected by the target. The controller processes the received light signal to deduce the amount of methane in the laser's path. For use in the airborne platform, we modified three aspects of the RMLD, by: (1) inserting an Erbium-doped optical fiber laser amplifier to increase the transmitted laser power from 10 mW to 5W; (2) increasing the optical receiver diameter from 10 cm to 25 cm; and (3) altering the laser wavelength from 1653 nm to 1618 nm. The modified RMLD system provides a path-integrated …
Date:
December 31, 2006
Creator:
Wainner, Richard T.; Frish, Mickey B.; Green, B. David; Laderer, Matthew C.; Allen, Mark G. & Morency, Joseph R.
Object Type:
Report
System:
The UNT Digital Library
High Efficiency LED Lamp for Solid-State Lighting
This report contains a summary of technical achievements during a three-year project to demonstrate high efficiency, solid-state lamps based on gallium nitride/silicon carbide light-emitting diodes. Novel chip designs and fabrication processes are described for a new type of nitride light-emitting diode with the potential for very high efficiency. This work resulted in the demonstration of blue light-emitting diodes in the one watt class that achieved up to 495 mW of light output at 350 mA drive current, corresponding to quantum and wall plug efficiencies of 51% and 45%, respectively. When combined with a phosphor in Cree's 7090 XLamp package, these advanced blue-emitting devices resulted in white light-emitting diodes whose efficacy exceeded 85 lumens per watt. In addition, up to 1040 lumens at greater than 85 lumens per watt was achieved by combining multiple devices to make a compact white lamp module with high optical efficiency.
Date:
December 31, 2006
Creator:
Ibbetson, James
Object Type:
Report
System:
The UNT Digital Library
Homogeneous and Supported Niobium Catalysts as Lewis Acid and Radical Catalysts
The synthesis of tetrachlorotetraphenylcyclopentadienyl group 5 metal complexes has been accomplished through two routes, one a salt metathesis with lithiumtetraphenylcyclopentadiende and the other, reaction with trimethyltintetraphenylcyclopentadiene. The reactants and products have been characterized by {sup 1}H and {sup 13}C({sup 1}H) NMR spectroscopy. The niobium complex promotes the silylcyanation of butyraldehyde. The grafting of metal complexes to silica gel surfaces has been accomplished using tetrakisdimethylamidozirconium as the metal precursor. The most homogeneous binding as determined by CP-MAS {sup 13}C NMR and infrared spectroscopy was obtained with drying at 500 C at 3 mtorr vacuum. The remaining amido groups can be replaced by reaction with alcohols to generate surface bound metal alkoxides. These bound catalysts promote silylcyanation of aryl aldehydes and can be reused three times with no loss of activity.
Date:
December 31, 2006
Creator:
Tikkanen, Wayne
Object Type:
Report
System:
The UNT Digital Library
Idaho Biodiesel Infrastructure Project: Final Report, December 2006
The Idaho Energy Division issued a Request for Proposal (RFP) on March 14, 2006, inviting qualified licensed fuel wholesalers, fuel retailers, and vehicle fleet operators to provide proposals to construct and/or install infrastructure for biodiesel utilization in Idaho. The intent was to improve the ability of private and/or non-Federal public entities in Idaho to store, transport, or offer for sale biodiesel within the state. The RFP provided up $100,000 for co-funding the projects with a minimum 50% cash cost match. Four contracts were subsequetnly awarded that resulted in three new bidodiesel storage facilities immediately serving about 45 fueling stations from Sandpoint to Boise. The project also attracted considerable media attention and Idaho became more knowledgeable about biodiesel.
Date:
December 31, 2006
Creator:
Crockett, John
Object Type:
Report
System:
The UNT Digital Library
Individual Particle Analysis of Ambient PM 2.5 Using Advanced Electron Microscopy Techniques
The overall goal of this project was to demonstrate a combination of advanced electron microscopy techniques that can be effectively used to identify and characterize individual particles and their sources. Specific techniques to be used include high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM), STEM energy dispersive X-ray spectrometry (EDX), and energy-filtered TEM (EFTEM). A series of ambient PM{sub 2.5} samples were collected in communities in southwestern Detroit, MI (close to multiple combustion sources) and Steubenville, OH (close to several coal fired utility boilers). High-resolution TEM (HRTEM) -imaging showed a series of nano-metal particles including transition metals and elemental composition of individual particles in detail. Submicron and nano-particles with Al, Fe, Ti, Ca, U, V, Cr, Si, Ba, Mn, Ni, K and S were observed and characterized from the samples. Among the identified nano-particles, combinations of Al, Fe, Si, Ca and Ti nano-particles embedded in carbonaceous particles were observed most frequently. These particles showed very similar characteristics of ultrafine coal fly ash particles that were previously reported. By utilizing HAADF-STEM, STEM-EDX, and EF-TEM, this investigation was able to gain information on the size, morphology, structure, and elemental composition of individual nano-particles collected in Detroit and Steubenville. The results showed …
Date:
December 31, 2006
Creator:
Keeler, Gerald J. & Morishita, Masako
Object Type:
Report
System:
The UNT Digital Library
The Influence of Radiation on Pit Solution Chemistry as it Pertains to the Transition from Metastable to Stable Pitting in Steels.
Previous work relevant to current efforts is summarized. A description of an improved version of a new electrochemical probe, the ArtPit, is given. The distinct feature of the probe for investigating metastable pitting of carbon steels is specified and compared to other approaches. The electrochemical response of the ArtPit under the gamma irradiation and elevated temperature conditions that occur at high level waste (HLW) storage tanks is presented. In particular, the Tafel slope determinations and chemical analyses of the ArtPit confined volume electrolyte are described. Based on results a possible approach for reducing the corrosion rate of HLW tank walls is suggested. Additional statistical analysis of the occurrence of short duration (passivated pits) and long term (stable pitting) electrochemical pulses (current surges) during exposure confirm that radiation enhances the occurrence of both more and smaller sized pits due to increased likelihood of repassivation.
Date:
December 31, 2006
Creator:
Galuszka-Muga, Barbara & Muga, Luis M.
Object Type:
Report
System:
The UNT Digital Library
An Integrated Approach to Characterizing Bypassed Oil in Heterogeneous and Fractured Reservoirs Using Partitioning Tracers
We explore the use of efficient streamline-based simulation approaches for modeling partitioning interwell tracer tests in hydrocarbon reservoirs. Specifically, we utilize the unique features of streamline models to develop an efficient approach for interpretation and history matching of field tracer response. A critical aspect here is the underdetermined and highly ill-posed nature of the associated inverse problems. We have investigated the relative merits of the traditional history matching ('amplitude inversion') and a novel travel time inversion in terms of robustness of the method and convergence behavior of the solution. We show that the traditional amplitude inversion is orders of magnitude more non-linear and the solution here is likely to get trapped in local minimum, leading to inadequate history match. The proposed travel time inversion is shown to be extremely efficient and robust for practical field applications. The streamline approach is generalized to model water injection in naturally fractured reservoirs through the use of a dual media approach. The fractures and matrix are treated as separate continua that are connected through a transfer function, as in conventional finite difference simulators for modeling fractured systems. A detailed comparison with a commercial finite difference simulator shows very good agreement. Furthermore, an examination of …
Date:
December 31, 2006
Creator:
Datta-Gupta, Akhil
Object Type:
Report
System:
The UNT Digital Library
INVESTIGATION OF THE TRANSFORMATION OF URANIUM UNDER IRON-REDUCING CONDITIONS: REDUCTION OF UVI BY BIOGENIC FEII/FEIII HYDROXIDE (GREEN RUST)
The recent identification of green rusts (GRs) as products of the reduction of FeIII oxyhydroxides by dissimilatory iron-reducing bacteria, coupled with the ability of synthetic (GR) to reduce UVI species to insoluble UO2, suggests that biogenic green rusts (BioGRs) may play an important role in the speciation (and thus mobility) of U in FeIII-reducing environments. The objective of our research was to examine the potential for BioGR to affect the speciation of U under FeIII-reducing conditions. To meet this objective, we designed and executed a hypothesis-driven experimental program to identify key factors leading to the formation of BioGRs as products of dissimilatory FeIII reduction, to determine the key factors controlling the reduction of UVI to UIV by GRs, and to identify the resulting U-bearing mineral phases. The results of this research significantly increase our understanding of the coupling of biotic and abiotic processes with respect to the speciation of U in iron-reducing environments. In particular, the reduction of UVI to UIV by BioGR with the subsequent formation of U-bearing mineral phases may be effective for immobilizing U in suboxic subsurface environments. This information has direct applications to contaminant transport modeling and bioremediation engineering for natural or enhanced in situ remediation …
Date:
December 31, 2006
Creator:
O'Loughlin, Edward J.; Scherer, Michelle M. & Kemner, Kenneth M.
Object Type:
Report
System:
The UNT Digital Library
Joining of Tungsten Armor Using Functional Gradients
The joining of low thermal expansion armor materials such as tungsten to high thermal expansion heat sink materials has been a major problem in plasma facing component (PFC) development. Conventional planar bonding techniques have been unable to withstand the high thermal induced stresses resulting from fabrication and high heat flux testing. During this investigation, innovative functional gradient joints produced using vacuum plasma spray forming techniques have been developed for joining tungsten armor to copper alloy heat sinks. A model was developed to select the optimum gradient architecture. Based on the modeling effort, a 2mm copper rich gradient was selected. Vacuum plasma pray parameters and procedures were then developed to produce the functional gradient joint. Using these techniques, dual cooling channel, medium scale mockups (32mm wide x 400mm length) were produced with vacuum plasma spray formed tungsten armor. The thickness of the tungsten armor was up to 5mm thick. No evidence of debonding at the interface between the heat sink and the vacuum plasma sprayed material was observed.
Date:
December 31, 2006
Creator:
O'Dell, John Scott
Object Type:
Report
System:
The UNT Digital Library