Novel High Temperature Materials for In-Situ Sensing Devices (open access)

Novel High Temperature Materials for In-Situ Sensing Devices

The overriding goal of this project was to develop gas sensor materials and systems compatible with operation at temperatures from 500 to 700 C. Gas sensors operating at these temperatures would be compatible with placement in fossil-energy exhaust streams close to the combustion chamber, and therefore have advantages for process regulation, and feedback for emissions controls. The three thrusts of our work included investigating thin film gas sensor materials based on metal oxide materials and electroceramic materials, and also development of microhotplate devices to support the gas sensing films. The metal oxide materials NiO, In{sub 2}O{sub 3}, and Ga{sub 2}O{sub 3} were investigated for their sensitivity to H{sub 2}, NO{sub x}, and CO{sub 2}, respectively, at high temperatures (T > 500 C), where the sensing properties of these materials have received little attention. New ground was broken in achieving excellent gas sensor responses (>10) for temperatures up to 600 C for NiO and In{sub 2}O{sub 3} materials. The gas sensitivity of these materials was decreasing as temperatures increased above 500 C, which indicates that achieving strong sensitivities with these materials at very high temperatures (T {ge} 650 C) will be a further challenge. The sensitivity, selectivity, stability, and reliability of …
Date: December 31, 2009
Creator: Solzbacher, F.; Virkar, A.; Rieth, L.; Kannan, S.; Chen, X. & Steinebach, H.
Object Type: Report
System: The UNT Digital Library
A Novel Low-Temperature Fiffusion Aluminide Coating for Ultrasupercritical Coal-Fried Boiler Applications (open access)

A Novel Low-Temperature Fiffusion Aluminide Coating for Ultrasupercritical Coal-Fried Boiler Applications

An ultrasupercritical (USC) boiler with higher steam temperature and pressure is expected to increase the efficiency of the coal-fired power plant and also decrease emissions of air pollutants. Ferritic/martensitic alloys have been developed with good creep strength for the key components in coal-fired USC plants. However, they typically suffer excessive steam-side oxidation, which contributes to one of main degradation mechanisms along with the fire-side corrosion in coal-fired boilers. As the steam temperature further increases in USC boilers, oxidation of the tube internals becomes an increasing concern, and protective coatings such as aluminide-based diffusion coatings need to be considered. However, conventional aluminizing processes via pack cementation or chemical vapor deposition are typically carried out at elevated temperatures (1000-1150 C). Thermochemical treatment of ferritic/martensitic alloys at such high temperatures could severely degrade their mechanical properties, particularly the alloy's creep resistance. The research focus of this project was to develop an aluminide coating with good oxidation resistance at temperatures {le} 700 C so that the coating processing would not detrimentally alter the creep performance of the ferritic/martensitic alloys. Nevertheless, when the aluminizing temperature is lowered, brittle Al-rich intermetallic phases, such as Fe{sub 2}Al{sub 5} and FeAl{sub 3}, tend to form in the coating, …
Date: December 31, 2009
Creator: Zhang, Ying
Object Type: Report
System: The UNT Digital Library
Security Classification Policy and Procedure: E.O. 12958, as Amended (open access)

Security Classification Policy and Procedure: E.O. 12958, as Amended

This report describes security classification policy and procedure, largely prescribed in a series of successive presidential executive orders issued over the past 50 years. This policy provides the rationale and arrangements for designating information officially secret for reasons of national security, and for its declassification as well.
Date: December 31, 2009
Creator: Kosar, Kevin R.
Object Type: Report
System: The UNT Digital Library
Simulating Potential Switchgrass Production in the United States (open access)

Simulating Potential Switchgrass Production in the United States

Using results from field trials of switchgrass (Panicum virgatum L.) in the United States, the EPIC (Environmental Policy Integrated Climate) process-level agroecosystem model was calibrated, validated, and applied to simulate potential productivity of switchgrass for use as a biofuel feedstock. The model was calibrated with a regional study of 10-yr switchgrass field trials and subsequently tested against a separate compiled dataset of field trials from across the eastern half of the country. An application of the model in a national database using 8-digit watersheds as the primary modeling unit produces 30-yr average switchgrass yield estimates that can be aggregated to 18 major watersheds. The model projects average annual switchgrass productivity of greater than 7 Mg ha-1 in the Upper Mississippi, Lower Mississippi, and Ohio watersheds. The major factors limiting simulated production vary by region; low precipitation is the primary limiting factor across the western half of the country, while moderately acidic soils limit yields on lands east of the Mississippi River. Average projected switchgrass production on all crop land in the continental US is 5.6 Mg ha-1. At this level of productivity, 28.6 million hectares of crop land would be required to produce the 16 billion gallons of cellulosic ethanol …
Date: December 31, 2009
Creator: Thomson, Allison M.; Izaurralde, Roberto C.; West, T. O.; Parrish, David J.; Tyler, Donald D. & Williams, Jimmy R.
Object Type: Report
System: The UNT Digital Library
Southern Nevada Alternative Fuels Demonstration Project (open access)

Southern Nevada Alternative Fuels Demonstration Project

The Southern Nevada Alternative Fuels Program is designed to demonstrate, in a day-to-day bus operation, the reliability and efficiency of a hydrogen bus operation under extreme conditions. By using ICE technology and utilizing a virtually emission free fuel, benefits to be derived include air quality enhancement and vehicle performance improvements from domestically produced, renewable energy sources. The project objective is to help both Ford and the City demonstrate and evaluate the performance characteristics of the E-450 H2ICE shuttle buses developed by Ford, which use a 6.8-liter supercharged Triton V-10 engine with a hydrogen storage system equivalent to 29 gallons of gasoline. The technology used during the demonstration project in the Ford buses is a modified internal combustion engine that allows the vehicles to run on 100% hydrogen fuel. Hydrogen gives a more thorough fuel burn which results in more power and responsiveness and less pollution. The resultant emissions from the tailpipe are 2010 Phase II compliant with NO after treatment. The City will lease two of these E-450 H2ICE buses from Ford for two years. The buses are outfitted with additional equipment used to gather information needed for the evaluation. Performance, reliability, safety, efficiency, and rider comments data will be …
Date: December 31, 2009
Creator: Hyde, Dan & Fast, Matthew
Object Type: Report
System: The UNT Digital Library
Test Program for High Efficiency Gas Turbine Exhaust Diffuser (open access)

Test Program for High Efficiency Gas Turbine Exhaust Diffuser

This research relates to improving the efficiency of flow in a turbine exhaust, and thus, that of the turbine and power plant. The Phase I SBIR project demonstrated the technical viability of “strutlets” to control stalls on a model diffuser strut. Strutlets are a novel flow-improving vane concept intended to improve the efficiency of flow in turbine exhausts. Strutlets can help reduce turbine back pressure, and incrementally improve turbine efficiency, increase power, and reduce greenhouse gas emmission. The long-term goal is a 0.5 percent improvement of each item, averaged over the US gas turbine fleet. The strutlets were tested in a physical scale model of a gas turbine exhaust diffuser. The test flow passage is a straight, annular diffuser with three sets of struts. At the end of Phase 1, the ability of strutlets to keep flow attached to struts was demonstrated, but the strutlet drag was too high for a net efficiency advantage. An independently sponsored followup project did develop a highly-modified low-drag strutlet. In combination with other flow improving vanes, complicance to the stated goals was demonstrated for for simple cycle power plants, and to most of the goals for combined cycle power plants using this particular exhaust …
Date: December 31, 2009
Creator: Norris, Thomas R.
Object Type: Report
System: The UNT Digital Library
Texas Department of Savings and Mortgage Lending Savings Institutions Annual Report: 2009 (open access)

Texas Department of Savings and Mortgage Lending Savings Institutions Annual Report: 2009

Report by the Texas Department of Saving & Mortgage Lending containing information tables with financial information on such things as bank assets, assets of associated business by county and equity capital.
Date: December 31, 2009
Creator: Texas. Department of Savings and Mortgage Lending.
Object Type: Report
System: The Portal to Texas History
Understanding China's Political System (open access)

Understanding China's Political System

This report provides an overview of contemporary PRC (People's Republic of China) politics by analyzing the main institutional actors and their interactions. The goal is not so much to provide the definitive study of the current political dynamics in China, but to offer a framework for examining and understanding PRC politics as they play out with respect to particular policies or issues.
Date: December 31, 2009
Creator: Dumbaugh, Kerry & Martin, Michael F.
Object Type: Report
System: The UNT Digital Library
A University Consortium on Low Temperature Combustion for High Efficiency, Ultra-Low Emission Engines (open access)

A University Consortium on Low Temperature Combustion for High Efficiency, Ultra-Low Emission Engines

The objective of the University consortium was to investigate the fundamental processes that determine the practical boundaries of Low Temperature Combustion (LTC) engines and develop methods to extend those boundaries to improve the fuel economy of these engines, while operating with ultra low emissions. This work involved studies of thermal effects, thermal transients and engine management, internal mixing and stratification, and direct injection strategies for affecting combustion stability. This work also examined spark-assisted Homogenous Charge Compression Ignition (HCCI) and exhaust after-treatment so as to extend the range and maximize the benefit of Homogenous Charge Compression Ignition (HCCI)/ Partially Premixed Compression Ignition (PPCI) operation. In summary the overall goals were:  Investigate the fundamental processes that determine the practical boundaries of Low Temperature Combustion (LTC) engines.  Develop methods to extend LTC boundaries to improve the fuel economy of HCCI engines fueled on gasoline and alternative blends, while operating with ultra low emissions.  Investigate alternate fuels, ignition and after-treatment for LTC and Partially Premixed compression Ignition (PPCI) engines.
Date: December 31, 2009
Creator: Assanis, Dennis N.; Atreya, Arvind; Chen, Jyh-Yuan; Cheng, Wai K.; Dibble, Robert W.; Edwards, Chris et al.
Object Type: Report
System: The UNT Digital Library
Water and Energy Sustainability: A Balance of Government Action and Industry Innovation (open access)

Water and Energy Sustainability: A Balance of Government Action and Industry Innovation

By completing the tasks and subtasks of the project, the Ground Water Protection Council (GWPC) through its state regulatory agency members and oil and gas industry partners, will bring attention to water quality and quantity issues and make progress toward water and energy sustainability though enhanced water protection and conservation thus enhancing the viability of the domestic fossil fuel industry. The project contains 4 major independent Tasks. Task 1 - Work Plan: Water-Energy Sustainability: A Symposium on Resource Viability. Task 2 - Work Plan: A Regional Assessment of Water and Energy Sustainability. Task 3 - Work Plan: Risk Based Data Management System-Water Water and Energy Module. Task 4 - Work Plan: Identification and Assessment of States Regulatory Programs Regarding Geothermal Heating and Cooling Systems. Each task has a specific scope (details given).
Date: December 31, 2009
Creator: Grunewald, Ben
Object Type: Report
System: The UNT Digital Library