Partner
UNT Libraries Government Documents Department
2,625
Oklahoma Historical Society
48
UNT Libraries Special Collections
22
Sterling Municipal Library
12
Oklahoma State Firefighters Museum
10
National Museum of the Pacific War/Admiral Nimitz Foundation
7
Alvin Community College
5
Archer Public Library
5
Abilene Christian University Library
4
Austin Memorial Library
4
49 More
Collection
Office of Scientific & Technical Information Technical Reports
2,452
Texas Digital Newspaper Program
98
Congressional Research Service Reports
83
Government Accountability Office Reports
71
Oklahoma Digital Newspaper Program
64
Tocker Foundation Grant
55
The Baytown Sun
12
The Gayly Oklahoman
11
Oklahoma State Firefighters Museum
10
Chickasha Newspaper Collection
9
89 More
Country
Decade
Year
Month
Day
Language
2,832 Matching Results
Results open in a new window/tab.
A strong hot spot theorem
None
Date:
July 1, 2003
Creator:
Bailey, David H. & Rudolph, Daniel J.
Object Type:
Report
System:
The UNT Digital Library
On the binary expansions of algebraic numbers
Employing concepts from additive number theory, together with results on binary evaluations and partial series, we establish bounds on the density of 1's in the binary expansions of real algebraic numbers. A central result is that if a real y has algebraic degree D > 1, then the number {number_sign}(|y|, N) of 1-bits in the expansion of |y| through bit position N satisfies {number_sign}(|y|, N) > CN{sup 1/D} for a positive number C (depending on y) and sufficiently large N. This in itself establishes the transcendency of a class of reals {summation}{sub n{ge}0} 1/2{sup f(n)} where the integer-valued function f grows sufficiently fast; say, faster than any fixed power of n. By these methods we re-establish the transcendency of the Kempner--Mahler number {summation}{sub n{ge}0}1/2{sup 2{sup n}}, yet we can also handle numbers with a substantially denser occurrence of 1's. Though the number z = {summation}{sub n{ge}0}1/2{sup n{sup 2}} has too high a 1's density for application of our central result, we are able to invoke some rather intricate number-theoretical analysis and extended computations to reveal aspects of the binary structure of z{sup 2}.
Date:
July 1, 2003
Creator:
Bailey, David H.; Borwein, Jonathan M.; Crandall, Richard E. & Pomerance, Carl
Object Type:
Article
System:
The UNT Digital Library
Distributed energy resources in practice: A case study analysis and validation of LBNL's customer adoption model
This report describes a Berkeley Lab effort to model the economics and operation of small-scale (<500 kW) on-site electricity generators based on real-world installations at several example customer sites. This work builds upon the previous development of the Distributed Energy Resource Customer Adoption Model (DER-CAM), a tool designed to find the optimal combination of installed equipment, and idealized operating schedule, that would minimize the site's energy bills, given performance and cost data on available DER technologies, utility tariffs, and site electrical and thermal loads over a historic test period, usually a recent year. This study offered the first opportunity to apply DER-CAM in a real-world setting and evaluate its modeling results. DER-CAM has three possible applications: first, it can be used to guide choices of equipment at specific sites, or provide general solutions for example sites and propose good choices for sites with similar circumstances; second, it can additionally provide the basis for the operations of installed on-site generation; and third, it can be used to assess the market potential of technologies by anticipating which kinds of customers might find various technologies attractive. A list of approximately 90 DER candidate sites was compiled and each site's DER characteristics and their …
Date:
February 1, 2003
Creator:
Bailey, Owen; Creighton, Charles; Firestone, Ryan; Marnay, Chris & Stadler, Michael
Object Type:
Report
System:
The UNT Digital Library
Biopower Technical Assessment: State of the Industry and the Technology
This report provides an assessment of the state of the biopower industry and the technology for producing electricity and heat from biomass. Biopower (biomass-to-electricity generation), a proven electricity generating option in the United States and with about 11 GW of installed capacity, is the single largest source of non-hydro renewable electricity. This 11 GW of capacity encompasses about 7.5 GW of forest product industry and agricultural industry residues, about 3.0 GW of municipal solid waste-based generating capacity and 0.5 GW of other capacity such as landfill gas based production. The electricity production from biomass is being used and is expected to continue to be used as base load power in the existing electrical distribution system. An overview of sector barriers to biopower technology development is examined in Chapter 2. The discussion begins with an analysis of technology barriers that must be overcome to achieve successful technology pathways leading to the commercialization of biomass conversion and feedstock technologies. Next, an examination of institutional barriers is presented which encompasses the underlying policies, regulations, market development, and education needed to ensure the success of biopower. Chapter 3 summarizes biomass feedstock resources, characteristics, availability, delivered prices, requirements for processing, and the impediments and barriers …
Date:
January 1, 2003
Creator:
Bain, R. L.; Amos, W. P.; Downing, M. & Perlack, R. L.
Object Type:
Report
System:
The UNT Digital Library
Highlights of Biopower Technical Assessment: State of the Industry and the Technology
This report summarizes the findings of the Biopower Technical Assessment, which reviews the state of the biopower industry and the technology for producing electricity and heat from biomass.
Date:
April 1, 2003
Creator:
Bain, R. L.; Amos, W. P.; Downing, M. & Perlack, R. L.
Object Type:
Report
System:
The UNT Digital Library
COMPARISON OF GKS CALCULATED CRITICAL ION TEMPERATURE GRADIENTS AND ITG GROWTH RATES TO DIII-D MEASURED GRADIENTS AND DIFFUSIVITIES
OAK-B135 The gyrokinetic equations predict that various drift type waves or modes can be unstable in a tokamak. For some of these modes, such as the ion temperature gradient (ITG) mode and the electron temperature gradient mode, there exists a critical gradient, above which the mode is unstable. Since the existence of unstable modes can cause increased transport, plasmas which are centrally heated tend to increase in temperature gradient until the modes become unstable. Under some conditions the increased transport can fix the gradient at the critical value. here they present a comparison between the measured ion temperature gradients and the critical gradient as calculated by a gyrokinetic linear stability (GKS) code. They also present the maximum linear growth rate as calculated by this code for comparison to experimentally derived transport coefficients. The results show that for low confinement mode (L-mode) discharges, the measured ion temperature gradient is significantly greater than the GKS calculated critical gradient over a large region of the plasma. This is the same region of the plasma where the ion thermal diffusivity is large. For high confinement mode (H-mode) discharges the ion temperature gradient is closer to the critical gradient, but often still greater than the …
Date:
April 1, 2003
Creator:
Baker, D. R.; Staebler, G. M.; Petty, C. C.; Greenfield, C. M. & Luce, T. C.
Object Type:
Article
System:
The UNT Digital Library
Fiber Optical Micro-Detectors for Oxygen Sensing in Power Plants Progress Report
In this report, initial results pertaining to the synthesis molybdenum clusters and characterization using absorption, optical microscopy, and x-ray powder diffraction are discussed. The synthesis was performed according to literature [1], but results from x-ray powder diffraction indicate that the synthesis did not give the desired compound. The absorption and optical microscopy indicate that the compound synthesized has properties similar to the desired Mo{sub 6}Cl{sub 12} clusters [2,3], so it is unclear as of yet what happened. The sample cell for performing high temperature spectroscopy on thin films of the molybdenum clusters at elevated temperature in a controlled gas environment was designed and an initial prototype was built.
Date:
January 1, 2003
Creator:
Baker, Gregory L.; Ghosh, Ruby N. & III, D.J. Osborn
Object Type:
Report
System:
The UNT Digital Library
Fiber Optical Micro-Detectors for Oxygen Sensing in Power Plants Progress Report
Mo{sub 6}Cl{sub 12}, a cluster compound whose luminescence depends on the ambient concentration of oxygen, is the basis for a real-time oxygen sensor for combustion applications. Previously, the properties of Mo{sub 6}Cl{sub 12} have largely been studied at room temperature; these studies have now been extended to 200 C. Optical microscopy shows that Mo{sub 6}Cl{sub 12} undergoes a steady change in color as it is heated from room temperature to 200 C, changing from canary yellow to crimson and then back to canary yellow. Concurrent thermal gravimetric analyses show a small weight loss for Mo{sub 6}Cl{sub 12} that is consistent with loss of water or HCl from the clusters. These changes are reversible. Absorption and fluorescence emission spectroscopy of Mo{sub 6}Cl{sub 12} heated to 200 C for two hours shows no change in the photophysical parameters compared to the control sample that was not heat cycled.
Date:
July 1, 2003
Creator:
Baker, Gregory L.; Ghosh, Ruby N. & III, D.J. Osborn
Object Type:
Report
System:
The UNT Digital Library
Fiber Optical Micro-Detectors for Oxygen Sensing in Power Plants Progress Report
More Mo{sub 6}Cl{sub 12} has been synthesized. We have found that previous ambiguous x-ray powder diffraction results are due to disruption of long-range order in the crystals during the heating stage of the synthesis. The quartz cell heaters have been redesigned and are able to heat the substrate. Initial films have been fabricated and are currently under investigation to determine optimal deposition conditions.
Date:
May 1, 2003
Creator:
Baker, Gregory L.; Ghosh, Ruby N. & III, D.J. Osborn
Object Type:
Report
System:
The UNT Digital Library
Nuclear criticality safety aspects of emergency response at the Los Alamos National Laboratory.
Emergency response at Los Alamos National Laboratory (LANL) is handled through a graded approach depending on the specific emergency situation . LANL maintains a comprehensive capability to respond to events ranging from minor facility events (alerts) through major community events (general emergencies), including criticality accidents . Criticality safety and emergency response apply to all activities involving significant quantities of fissile material at LANL, primarily at Technical Area 18 (TA-18, the Los Alamos Critical Experiments Facility) and Technical Area 55 (TA-55, the Plutonium Facility). This discussion focuses on response to a criticality accident at TA-55; the approach at TA-18 is comparable .
Date:
January 1, 2003
Creator:
Baker, J. S. (James S.)
Object Type:
Article
System:
The UNT Digital Library
INEEL Biotechnology for Oilfield Application--Microbial Enhanced Oil Recovery FY-03 Report
The Idaho National Engineering and Environmental Laboratory (INEEL) Biotechnology for Oilfield Operations program supports development, engineering, and application of biotechnology for exploration and production. This continuing INEEL program also supports mitigation of detrimental field conditions. The program is consistent with the United States Department of Energy mission to ¡§promote activities and policies through its oil technology and natural gas supply programs to enhance the efficiency and environmental quality of domestic oil and natural gas exploration, recovery, processing, transport, and storage.¡¨ In addition, the program directly supports the focus areas of Reservoir Life Extension; Advanced Drilling, Completion and Stimulation Systems; Effective Environmental Protection; and Cross Cutting Areas. The program is enhanced by collaborative relationships with industry and academia. For fiscal year 2003, the program focused on production and characterization of biological surfactants from agricultural residuals and the production and application of reactive microbial polymers. This report specifically details: 1. Use of a chemostat reactor operated in batch mode for producing surfactin, with concomitant use of an antifoam to prevent surfactant loss. The program achieved production and recovery of 0.6 g/L of surfactin per 12 hr. 2. Characterization of surfactin produced from agricultural residuals with respect to its ability to mediate changes …
Date:
November 1, 2003
Creator:
Bala, G. A.; Bruhn, D. F.; Fox, S. L.; Noah, K. S.; Schaller, K. D.; Robertson, E. P. et al.
Object Type:
Report
System:
The UNT Digital Library
ADVANCED FLUE GAS CONDITIONING AS A RETROFIT UPGRADE TO ENHANCE PM COLLECTION FROM COAL-FIRED ELECTRIC UTILITY BOILERS
The U.S. Department of Energy and ADA Environmental Solutions are engaged in a project to develop commercial flue gas conditioning additives. The objective is to develop conditioning agents that can help improve particulate control performance of smaller or under-sized electrostatic precipitators on utility coal-fired boilers. The new chemicals will be used to control both the electrical resistivity and the adhesion or cohesivity of the fly ash. There is a need to provide cost-effective and safer alternatives to traditional flue gas conditioning with SO{sub 3} and ammonia. During this reporting quarter, installation of a liquid flue gas conditioning system was completed at the American Electric Power Conesville Plant, Unit 3. This plant fires a bituminous coal and has opacity and particulate emissions performance issues related to fly ash re-entrainment. Two cohesivity-specific additive formulations, ADA-44C and ADA-51, will be evaluated. In addition, ammonia conditioning will also be compared.
Date:
January 1, 2003
Creator:
Baldrey, Kenneth E.
Object Type:
Report
System:
The UNT Digital Library
ADVANCED FLUE GAS CONDITIONING AS A RETROFIT UPGRADE TO ENHANCE PM COLLECTION FROM COAL-FIRED ELECTRIC UTILITY BOILERS
The U.S. Department of Energy and ADA Environmental Solutions are engaged in a project to develop commercial flue gas conditioning additives. The objective is to develop conditioning agents that can help improve particulate control performance of smaller or under-sized electrostatic precipitators on utility coal-fired boilers. The new chemicals will be used to control both the electrical resistivity and the adhesion or cohesivity of the fly ash. There is a need to provide cost-effective and safer alternatives to traditional flue gas conditioning with SO{sub 3} and ammonia. During this reporting quarter, two cohesivity-specific additive formulations, ADA-44C and ADA-51, were evaluated in a full-scale trial at the American Electric Power Conesville plant. Ammonia conditioning was also evaluated for comparison. ADA-51 and ammonia conditioning significantly reduced rapping and non-rapped particulate re-entrainment based on stack opacity monitor data. Based on the successful tests to date, ADA-51 will be evaluated in a long-term test.
Date:
February 1, 2003
Creator:
Baldrey, Kenneth E.
Object Type:
Report
System:
The UNT Digital Library
The Reaction Kinetics of LiD with Water Vapor
The interaction of LiD with water vapor in the partial pressure range of 10{sup -7} Torr to 20 Torr has been investigated. The reaction probability of water with pure LiD cleaved in an ultra high vacuum environment was obtained using the modulated molecular beam technique. This probability was 0.11 and independent of LiD surface temperature suggesting a negligible activation energy for the reaction in agreement with quantum chemical calculations. The value gradually reduced, however, to .007 as the surface concentration of oxygen containing product (LiOH), which was monitored in-situ by Auger electron spectroscopy on the reaction zone, approached full coverage. As the hydroxide film grew beyond a monolayer, the phase lag of hydrogen product increased from zero to 20 degrees and the reaction probability reduced further until it approached our detection limit ({approx} 10{sup -4}). This phase lag was attributed to a diffusion limited process in this regime. In separate experiments, the film growth has been studied in nitrogen atmosphere with 100% relative humidity using thermogravimetric analysis (TGA) and in air with 50% relative humidity utilizing scanning electron microscopy (SEM). For exposures to environment with high water concentrations and for micrometer thick films, the reaction probability reduced to 4 x …
Date:
April 1, 2003
Creator:
Balooch, M; Dinh, L N & Calef, D F
Object Type:
Report
System:
The UNT Digital Library
Strategic Petroleum Reserve
None
Date:
October 1, 2003
Creator:
Bamberger, Robert L.
Object Type:
Report
System:
The UNT Digital Library
A NOVEL SENSOR AND MEASUREMENT SYSTEM FOR FIRESIDE CORROSION MONITORING IN COAL-FIRED BOILERS
Fireside corrosion in coal-fired power plants is a major obstacle to increase the overall efficiency for power producers. The increased use of opportunity fuels and low emission combustion modes have aggravated the corrosion on boiler tube walls in power plants. Corrosion-induced equipment failure could lead to catastrophic damage and inflict significant loss of production and cost for repair. Monitoring fireside corrosion in a reliable and timely manner can provide significant benefits to the plant operation. Current corrosion inspection and measurement are typically performed during scheduled maintenance outages, which is often after the damage is done. In the past, there have been many attempts to develop real time continuous corrosion monitoring technologies. However, there is still no short-term, online corrosion monitoring system commercially available for fireside corrosion to date due to the extremely harsh combustion environment. This report describes the results of a laboratory feasibility study on the development effort of a novel sensor for on-line fireside corrosion monitoring. A novel sensor principle and thin-film technologies were employed in the corrosion sensor design and fabrication. The sensor and the measurement system were experimentally studied using laboratory muffle furnaces. The results indicated that an accurate measure of corrosion rate could be made …
Date:
March 1, 2003
Creator:
Ban, Heng & Li, Zuoping
Object Type:
Report
System:
The UNT Digital Library
CRACK GROWTH ANALYSIS OF SOLID OXIDE FUEL CELL ELECTROLYTES
Defects and Flaws control the structural and functional property of ceramics. In determining the reliability and lifetime of ceramics structures it is very important to quantify the crack growth behavior of the ceramics. In addition, because of the high variability of the strength and the relatively low toughness of ceramics, a statistical design approach is necessary. The statistical nature of the strength of ceramics is currently well recognized, and is usually accounted for by utilizing Weibull or similar statistical distributions. Design tools such as CARES using a combination of strength measurements, stress analysis, and statistics are available and reasonably well developed. These design codes also incorporate material data such as elastic constants as well as flaw distributions and time-dependent properties. The fast fracture reliability for ceramics is often different from their time-dependent reliability. Further confounding the design complexity, the time-dependent reliability varies with the environment/temperature/stress combination. Therefore, it becomes important to be able to accurately determine the behavior of ceramics under simulated application conditions to provide a better prediction of the lifetime and reliability for a given component. In the present study, Yttria stabilized Zirconia (YSZ) of 9.6 mol% Yttria composition was procured in the form of tubes of length …
Date:
October 1, 2003
Creator:
Bandopadhyay, S. & Nagabhushana, N.
Object Type:
Report
System:
The UNT Digital Library
Oxygen Transport Ceramic Membranes
None
Date:
August 1, 2003
Creator:
Bandopadhyay, S. & Nagabhushana, N.
Object Type:
Report
System:
The UNT Digital Library
Oxygen Transport Ceramic Membranes
The present quarterly report describes some of the initial studies on newer compositions and also includes newer approaches to address various materials issues such as in metal-ceramic sealing. The current quarter's research has also focused on developing a comprehensive reliability model for predicting the structural behavior of the membranes in realistic conditions. In parallel to industry provided compositions, models membranes have been evaluated in varying environment. Of importance is the behavior of flaws and generation of new flaws aiding in fracture. Fracture mechanics parameters such as crack tip stresses are generated to characterize the influence of environment. Room temperature slow crack growth studies have also been initiated in industry provided compositions. The electrical conductivity and defect chemistry of an A site deficient compound (La{sub 0.55}Sr{sub 0.35}FeO{sub 3}) was studied. A higher conductivity was observed for La{sub 0.55}Sr{sub 0.35}FeO{sub 3} than that of La{sub 0.60}Sr{sub 0.40}FeO{sub 3} and La{sub 0.80}Sr{sub 0.20}FeO{sub 3}. Defect chemistry analysis showed that it was primarily contributed by a higher carrier concentration in La{sub 0.55}Sr{sub 0.35}FeO{sub 3}. Moreover, the ability for oxygen vacancy generation is much higher in La{sub 0.55}Sr{sub 0.35}FeO{sub 3} as well, which indicates a lower bonding strength between Fe-O and a possible higher catalytic …
Date:
November 1, 2003
Creator:
Bandopadhyay, S.; Nagabhushana, N.; Eagar, Thomas W.; Larson, Harold R.; Arroyave, Raymundo; Zhou, X. D. et al.
Object Type:
Report
System:
The UNT Digital Library
Oxygen Transport Ceramic Membranes Quarterly Report
In the present quarter, experiments are presented on ceramic/metal interactions of Zirconia/Ni-B-Si system and with a thin Ti coating deposited on zirconia surface. Processing of perovskites of LSC, LSF and LSCF composition for evaluation of mechanical properties as a function of environment are begun. The studies are to be in parallel with LSFCO composition to characterize the segregation of cations and slow crack growth in environmental conditions. La{sub 1-x}Sr{sub x}FeO{sub 3-d} has also been characterized for paramagnetic ordering at room temperature and the evolution of magnetic moments as a function of temperature are investigated. Investigation on the thermodynamic properties of the membrane materials are continued to develop a complete model for the membrane transport.
Date:
January 1, 2003
Creator:
Bandopadhyay, Sukumar & Nagabhushana, Nagendra
Object Type:
Report
System:
The UNT Digital Library
Oxygen Transport Ceramic Membranes Quarterly Report
In the present quarter, the possibility of using a more complex interfacial engineering approach to the development of reliable and stable oxygen transport perovskite ceramic membranes/metal seals is discussed. Experiments are presented and ceramic/metal interactions are characterized. Crack growth and fracture toughness of the membrane in the reducing conditions are also discussed. Future work regarding this approach is proposed are evaluated for strength and fracture in oxygen gradient conditions. Oxygen gradients are created in tubular membranes by insulating the inner surface from the reducing environment by platinum foils. Fracture in these test conditions is observed to have a gradient in trans and inter-granular fracture as opposed to pure trans-granular fracture observed in homogeneous conditions. Fracture gradients are reasoned to be due to oxygen gradient set up in the membrane, variation in stoichiometry across the thickness and due to varying decomposition of the parent perovskite. The studies are useful in predicting fracture criterion in actual reactor conditions and in understanding the initial evolution of fracture processes.
Date:
January 1, 2003
Creator:
Bandopadhyay, Sukumar & Nagabhushana, Nagendra
Object Type:
Report
System:
The UNT Digital Library
Superconducting Quadrupole Arrays for Multiple Beam Transport
The goal of this research was to develop concepts for affordable, fully functional arrays of superconducting quadrupoles for multi-beam transport and focusing in heavy ion fusion (HIF)accelerators. Previous studies by the Virtual National Laboratory (VNL) collaboration have shown that the multi-beam transport system (consisting of alternating gradient quadrupole magnets, a beam vacuum system, and the beam monitor and control system) will likely be one of the most expensive and critical parts of such an accelerator. This statement is true for near-term fusion research accelerators as well as accelerators for the ultimate goal of power production via inertial fusion. For this reason, research on superconducting quadrupole arrays is both timely and important for the inertial fusion energy (IFE) research program. This research will also benefit near-term heavy ion fusion facilities such as the Integrated Research Experiment (IRE)and/or the Integrated Beam Experiment (IBX). We considered a 2-prong approach that addresses the needs of both the nearer and longer term requirements of the inertial fusion program. First, we studied the flat coil quadrupole design that was developed by LLNL; this magnet is 150 mm long with a 50 mm aperture and thus is suitable for near term experiments that require magnets of a …
Date:
October 1, 2003
Creator:
Bangerter, Rainer Meinke Carl Goodzeit Penny Ball Roger
Object Type:
Report
System:
The UNT Digital Library
Analysis of CASES-99 Lidar and Turbulence Data in Support of Wind Turbine Effects: April 1, 2001 to Januay 31, 2003
The nocturnal low-level jet (LLJ) of the Great Plains of the central United States has been identified as a promising source of high-momentum wind flow for wind energy. The acceleration of the winds after sunset above the surface produces a jet profile in the wind velocity, with maximum speeds that often exceed 10 m s-1 or more at heights near 100 m or more. These high wind speeds are advantageous for wind energy generation. The high speeds aloft, however, also produce a region of high shear between the LLJ and the earth's surface, where the nocturnal flow is often calm or nearly so. This shear zone below the LLJ generates atmospheric waves and turbulence that can cause strong vibration in the turbine rotors. It has been suggested that these vibrations contribute to premature failures in large wind turbines, which, of course, would be a considerable disadvantage for wind energy applications. In October 1999, a field project called the Cooperative Atmosphere-Surface Exchange Study 1999 campaign, or CASES-99, was conducted in southeastern Kansas to study the nocturnal stable boundary layer. One of the instruments deployed during CASES-99 was the High-Resolution Doppler Lidar, a new scanning, remote-sensing, wind-mapping instrument.
Date:
June 1, 2003
Creator:
Banta, R. M.
Object Type:
Report
System:
The UNT Digital Library
Simulations with different lattice Dirac operators for valence and sea quarks
None
Date:
January 1, 2003
Creator:
Bar, Oliver; Rupak, Gautam & Shoresh, Noam
Object Type:
Article
System:
The UNT Digital Library